Just another alternator charging, battery thread - help for new owners?

[Kbarnes0]

Note, this post ended up way longer than I anticipated and I will update some images tomorrow as I think others may also.

Also, Without diving to far in. Im new to forums, but if you dive in searching for info. and see multiple posts from a user, double check the items in their signature for links. very helpful info for the common items. Such easy access I havent thanked them yet....

Its Ideal to get a feel for the year that your rig was last used. This can be by notes on the filters/ date codes on batts or tires. Main tool for diagnosis is a digital multi meter DMM

New to the forum and trucks. The info and support is great. I wanted to give a run down on my findings for a non charging rig. Your rig wont like much of anything if this system isnt operating correctly, I.E. Trans issues, Lights, and I think CTIS. There are many posts about all the related items, from truck year-equipment-use-and everything from the battery to the belts. I want to touch on a few things i picked up from reading the posts,TM's and general observations. Hoping that this can help someone in the future along with the other posts. To start, I have a general knowledge of trouble shooting, but plan on laying it out in a simple way so it will help all on any level. Of coarse there are a few things I learned the hard way and want to share a few tips that I found useful and maybe others can supply some also.

Ive typically referred to the main Voltage as the 12V in the auto industry. Most of what i have seen here is that it is referred to the Desired output voltage of 14V-28V

DO YOU HAVE A BATTERY TERMINAL DIAGRAM?

First, Batteries. Regardless of what direction you go with style or brand, If you dont know the history and are having trouble with them it may be time to start there. A standard car/ truck battery is basic in the batt/alt system. From reading most peoples posts , and what they are up against is wanting to run a rig on the Batts that were in the rig when they got it. This system comprised as four batteries factory can be modified in many ways. Operating with a 12V and 24V system with multiple batteries brings a large requirement for them to work together. From my understanding, Batteries can have a number of issues. This can vary from style- AGM, Lead acid, AKA low maintenance- No maintenance (maintenance free) Charge history, odd ball batteries thrown in, over charge or constant running low and overworking. The next stop would be the battery cables and connections.
I found my truck (M1090 Runner with jump) with the 6T AGM's from what looked like the 05 era. When it was on the trailer I had everything hooked up trying to fire it up to drive it off. Two things- one the trans doesnt like having low voltage and it didnt want to crank with my arsenal of valtage hooked up. Mostly because of lack of working on the rigs, trying to be quick. Finally hooked up an air line to undo the brakes and tow off the trailer. Then found the Batt cover in the bed later that day I did have two slave batts,two jump boxes and a charger on it... Just doing my thing with no luck.

Batt style. I decided to run the factory setup (stock as a rock) as I knew this would allow me to get where i wanted to be asap. After looking at some of the forums and posts the arrangements of styles can very. 2) 8D's. 4-6 Group31's. 4) 6T's like factory. I used the factory setup and retained the hold down and cables ( all in good condition). If your terminals and cables are shot ,might lean you in the direction of for different batt setups. BTW if still in place, the thing in the center of the hold down (curly que wire with a wand with red LED is for testing lead acid batteries).

Advanced testing of old batteries will tell you what you need if you are trying to keep them in the equation. Snap on testers test each asspect of the battery and will give a health report.
Batteries need to have good health. If you know the history it will give you a piece of mind and will answer a lot of questions. Clean terminals and good ground at the box

The variations around the box to my understanding is related to year/ series of rig. On the right side it can have a simple plug for a slave cable to jump power to rigs. From my reading- Some will have a larger box with a battery disconnect switch on the bottom and disconnects inside?

Next up is the Junction style under the spare tire. Depending on the rig this can be a Polarity Protection Device, Brand (SURE POWER PROTECTION DEVICE) only has the 12V and 24V wires in and 12V and 24V wires out. On the output side it should reflect a Slight drop (roughly .7V) This terminal feeds to the cab main power distribution panel. PDP. Note that the PDP has a specific layout with 12V and 24V Relays and Circuit breakers. 24V relays have 5 terminals and 12V have 4? Double check the relays are appropriate for the placement. Ive seen many images where lots of them are missing on rigs. This unit has diods in it to protect against hooking up the DC voltage incorrectly.

The other style is the LBCD - (load battery control device) Brand (NEIHOFF) It has the same inputs and outputs that the PPD, but has a harness (five wires) that ties into it to manage the charge control from the Alt. based on battery voltages and charge state. It also has An LED to let say what stat it is in. (see the Neihoff links for info later)

From my readings, many have found issues here with a loose terminal, broken stud when trying to loosen the nut. Testing the voltage on the input and output side will let you know the state of the connections. and output. Then checking the voltage at the PDP, and at the ALT for both 14V and 28V.

PDP. From what ive seen the K11 is the exciter relay tied into the oil pressure signal to the ALT to rectify/energize the charging state?

NIehoff has great diag. flow charts. Once you get the numbers from your ALT/REG and what type of box under the spare tire.

At the Alt. Factory style 100Amp. You will find that you may have a variation of ALts. Neihoff N1506 with my understanding is the N3030 regulator atttached (NO LEDS) The other is the N1509 (with LEDS) which i believe is a later model that can be on earlier rigs, mine being 94 with a PPD rather that the LBCD.

ON the regulator you will find the front terminal (closet to the radiator front of engine) is the 28V signal to tell the ALt to energize (start charging) This signal voltage is sent after the oil pressure signal is satisfied at 15PSI? Main function is to allow the engine start function to complete and RPM to satisfy before full draw of the Alt can be ignited to cause a strain. AKA excessive noise belt slipping.

The key is to remove the front terminal on the Voltage Regulator and test the voltage with the engine running at the wire that feeds to the regulator. DO you have 24V? This is the Excite, Exciter wire that is mentioned so much. The wire can have many issues to why it doesnt provide the voltage to Ignite(rectify) the ALT. Some will say its designed to operate a certain way so fix it piece by piece. I can Agree with that to an extent. I feel most of our use of these trucks will be under stated for the life of the consumable parts. The Key that is mentioned so many times is an excite wire from the fuel solenoid positive. It is a keyed on signal that will tell (excite/start) the ALT to charge. Not a factory solution, but in terms of most uses will fill the needs.

If you have a runner and dont have 24V to the front terminal to the REG. it is a simple test ti excite the ALT. Easiest is the 24V from the lug at the ALT. Jump to the front lug of the REG to tell it to fire up the ALT charge circuit. Otherwise you can get 24V from the PDP, PPD, or straight form the 24v Batt signal to try to energize the charge function.

NOTICE- THE WIRE CONFIGURATION OF THE VOLT/REG.... 5 WIRE FOR EARLIER MODELS 3030. 6 WIRES ON 3207. THIS WILL BE IMPORTANT IF YOU TEST OUT FOR ALT/REG.

Alternator, Niehoff is the brand. 100amp factory. seen some 200amp from Hummers installed but requires different PDP etc.as they are rated at the factory 100amp.

Once you know your model you can search the Flow chart for diag. from Neihoff. Ive searched the site and started down a link to find it was the wrong ALT or REG. Get the numbers from the equipment on your rig.

From Niehoff's flow chart. When you get the flow chart for your model ALT. It is critical to understand the terminology of each item. Based on the images, B-....so Negative. Then B+ for 14V and 28V. The main lugs. (Note the washers between the + lugs are fusible links. Havent found much out other than that they are there.)

I started on this flow chart and had to talk a day to get in the groove.(most likely due to sitting around to long)
I found the term Connector harness/ alt. a little confusing as they dont give a description beyond that of images. One main ket is when theu mention to jump from the Alt to the B- they are talking about the ground on the alt to the chassis. Not the B- terminal of the reg., The main things to realize is in that flow chart they are talking about . There are three components when the alt to reg harness is disconnected. the B+14V ---B+28V---B- as in negative. The connection between the ALT and Reg had its own designation and purpose of the voltages. They are labeled A-E on terminals but have designations of the different positive voltages and ground. Its interesting how they list them. I messed up on one the first. It is key to recognize the diff between B- on the harness (Between the alt and reg) and B- on the ALt. A on the harness to B- AKA Ground will energize the fields creating a magnetism on the center shaft of the ALT. when you do this jump you can hod a piece of metal by the center shaft and feel it pull the it in as a magnet. Pics will help spell this out.

When testing the harness alt to reg With good batts you can do some major welding/frying of the leads from the alt. I found a wire with a butt connector was best sutied to protect shorts between lugs. ( I shorted one out and had to clean it up. wasnt pretty, much different form 12V

The main part is getting down to the main issue. So often do we find that a connection or a simple item is the Hello moment. The understanding of these ALTs being brush less and pretty stout should allow some confidence in the surrounding items.

I hope this helps. I will add images for the descriptions above, WOuld love others input as ive just dove in ready to make something happen.

Im after a N3207 Regulator if you have one

Cheers

 

[mechanicjim]

for the LMTV/FMTV the history of C.E.Niehoff Alternators is 100 amp N1506, then N1509 then N1511, "260 amp upgrade" N1224 200-260A 28V, 140A 14V, then the optional N1313 300 amp 14V/28V. note there is a PS Mag article(PS 783 page 14 feb 1 about army obsoleting the 100 amps in favor of the 260 amps.
on all the C.E.Niehoffs dual output units the output amperage is limited based on the total, so depending on how much you pull on one side limits what the other side can produce.
parts and replacement items are technically available from C.E.Niehoff military distributors and because of ITAR reasons you need to fill out EUC form for replacements. and yes even thought the GOV let you get a truck already they treat spares as part of the "weapon" system so new replacements require paperwork.
the PPD is basically didoes to protect from reverse hookup. the LBCD is didoes with added capacitors to act like a "simulated" battery, this allows the LBCD to signal the Battery disconnect to remove battereis while running and to trickle charge them till they are high enough voltage to rejoin the system. simply the army overloads the alternator and the LBCD allows it to catch its breath while keeping the truck running.

 

[Ronmar]

for the LMTV/FMTV the history of C.E.Niehoff Alternators is 100 amp N1506, then N1509 then N1511, "260 amp upgrade" N1224 200-260A 28V, 140A 14V, then the optional N1313 300 amp 14V/28V. note there is a PS Mag article(PS 783 page 14 feb 1 about army obsoleting the 100 amps in favor of the 260 amps.
on all the C.E.Niehoffs dual output units the output amperage is limited based on the total, so depending on how much you pull on one side limits what the other side can produce.
parts and replacement items are technically available from C.E.Niehoff military distributors and because of ITAR reasons you need to fill out EUC form for replacements. and yes even thought the GOV let you get a truck already they treat spares as part of the "weapon" system so new replacements require paperwork.
the PPD is basically didoes to protect from reverse hookup. the LBCD is didoes with added capacitors to act like a "simulated" battery, this allows the LBCD to signal the Battery disconnect to remove battereis while running and to trickle charge them till they are high enough voltage to rejoin the system. simply the army overloads the alternator and the LBCD allows it to catch its breath while keeping the truck running.

which is why the later/larger LMTV alts are not necessarily backward compatible as they interact with the LBCD which the A0’s do not have...

 

[JD4044M]

Using this write up to check mine out. 1995 M1078 AO 100 Amp Dual Voltage system. At the 24 V Outlet next to the batteries it is 25.38 V running and 25.22 V off. Seems low to me on the running? Battery's after 2 days of driving, starting, radio on ect they all read 12.69--12.70 volts after sitting all night unhooked which is a full charge. So there not discharging when operating the truck. Raised the Cab to check voltages running. Main Lugs on the Alternator are reading 12.73 and 25.23 VDC and the little Red Cap Wire was 16.80 VDC Yellow Wire 24.32 VDC I think this is the Regulator mounted on the Alternator. Nothing seemed to jump up on a high idle except the Red cap wire went to 17.78 VDC Yellow wire 24.68 VDC. Have heard about adjusting the voltage up here but not sure this model? Where do I go from here? No Green/Red LED Lights I can see? Just took these pictures and yes that was the regulator. Still haven't washed the truck since last Sept!

 

[Ronmar]

The wire with the yellow heat-shrink on the forward reg terminal feeds 24V from relay K11 when the oil pressure goes over 15 PSI. Looks like it is being told to generate.

The terminal with the red cap is a field sense output. In your A0 it doesn’t do anything except feed up to the STE connector under the drivers dash for testing purposes. It is a way to tell how hard the alt is being told to work. I believe It is actually an AC voltage(pulsed DC/square wave), but I haven’t gotten a chance to put a scope on it. Since this is a brushless alt they are fed a pulsed excitation which is rectified back to DC field current on the rotor to excite the spinning field windings. In the A1/A1R it is used by the LBCD to disconnect the batteries and put them on a trickle charge when the alt reaches it’s output limit, so it doesn’t fry and can keep powering the truck on it’s mission.

The fact you are seeing activity on the field sense line(F-) means the reg is telling the alt to do something. But you should be seeing 14.1V and 28.2V on the main terminals and at the batteries. So it could be that some of the field diodes are shot and it cannot generate full field current on the rotor, or some of the output rectifier diodes are shot and it simply cannot boost the voltage high enough to meet it’s specified output.

I can think of 2 things to check besides all your connections and ground straps(alt to frame and engine to frame near starter are intact). These alts behave weird if they don’t see a valid 12/24V bank at the other end of the line. One indication of this is pulsing. “Ok, lets power up, oops, bats are not good, shutdown... Ok, lets power up, oops, batts no good, shutdown... repeat” bad connections or bad batts could cause this.


1. Measure the DC voltage outputs at the alt with the meter set for AC voltage. If the rectifier has issues, it will be skipping DC segments, which will look to the meter like AC voltage. This is known as ripple and should in a perfect world be in milivolts... if it is a larger AC voltage, the rectifier is probably at fault...

2. Disconnect the alternator 14 and 24V cables and insulate and secure them so they don’t short to frame or each other. Start the truck and measure the now unloaded voltage at the 14 and 28v connections on the alternator. If you get 14.1/28.2 I would suspect something is wrong with the rotor field diode pack or perhaps the regulator and it just cannot make enough output to float the battery voltage up to 14.1/28.2 against the battery load and powering the truck...

 

[JD4044M]

I was hoping I did not need a new alternator. Cheaper Parts are more fun to buy! I like the above information easier to understand then a TM! Thanks now I can do more testing, I was going to re/do the frame ground cable connections. I copied what you said to take out to my truck tomorrow.

 

[JD4044M]

No Parts to Buy is even better! OK I disconnected everything and clean brite all cable connections, threaded posts and negative on the Alternator. Both ends of the frame ground too. Did a test for voltage it was all over the place?? Shut the engine off hooked it all back up again. Started truck and noticed the voltage jumped at the Alternator!! Let it set for a min or too running and measured the Batteries again. They were 24.50 when I started the truck due to all the tests. Now they were 13.60-14.00 VDC and 27.90 at the Plug. Never charged that high before and they seemed more even? I left them hooked up to see what a few days does now. The Neg. on the Alternator did need a little cleaning wear you can't see. The others were OK under the sealer still cleaned them good. So not sure which connection was bad or a combo of more then one just not the best? It works now and that could have been big bucks!!

 

[frank8003]

Grounds is the other half.
There is lots of 'em..................

Just put Her back the way She was built the first time.
Wire Wheel, Scotch-bright, sandpaper, Emory cloth,
...........and use applicable torque on fasteners, with NEW washers just like the TM says to do.
Just do it once, good for another 10 years!

 

[Mullaney]

Note, this post ended up way longer than I anticipated and I will update some images tomorrow as I think others may also.

Also, Without diving to far in. Im new to forums, but if you dive in searching for info. and see multiple posts from a user, double check the items in their signature for links. very helpful info for the common items. Such easy access I havent thanked them yet....

Its Ideal to get a feel for the year that your rig was last used. This can be by notes on the filters/ date codes on batts or tires. Main tool for diagnosis is a digital multi meter DMM

New to the forum and trucks. The info and support is great. I wanted to give a run down on my findings for a non charging rig. Your rig wont like much of anything if this system isnt operating correctly, I.E. Trans issues, Lights, and I think CTIS. There are many posts about all the related items, from truck year-equipment-use-and everything from the battery to the belts. I want to touch on a few things i picked up from reading the posts,TM's and general observations. Hoping that this can help someone in the future along with the other posts. To start, I have a general knowledge of trouble shooting, but plan on laying it out in a simple way so it will help all on any level. Of coarse there are a few things I learned the hard way and want to share a few tips that I found useful and maybe others can supply some also.

Ive typically referred to the main Voltage as the 12V in the auto industry. Most of what i have seen here is that it is referred to the Desired output voltage of 14V-28V

DO YOU HAVE A BATTERY TERMINAL DIAGRAM?

First, Batteries. Regardless of what direction you go with style or brand, If you dont know the history and are having trouble with them it may be time to start there. A standard car/ truck battery is basic in the batt/alt system. From reading most peoples posts , and what they are up against is wanting to run a rig on the Batts that were in the rig when they got it. This system comprised as four batteries factory can be modified in many ways. Operating with a 12V and 24V system with multiple batteries brings a large requirement for them to work together. From my understanding, Batteries can have a number of issues. This can vary from style- AGM, Lead acid, AKA low maintenance- No maintenance (maintenance free) Charge history, odd ball batteries thrown in, over charge or constant running low and overworking. The next stop would be the battery cables and connections.
I found my truck (M1090 Runner with jump) with the 6T AGM's from what looked like the 05 era. When it was on the trailer I had everything hooked up trying to fire it up to drive it off. Two things- one the trans doesnt like having low voltage and it didnt want to crank with my arsenal of valtage hooked up. Mostly because of lack of working on the rigs, trying to be quick. Finally hooked up an air line to undo the brakes and tow off the trailer. Then found the Batt cover in the bed later that day I did have two slave batts,two jump boxes and a charger on it... Just doing my thing with no luck.

Batt style. I decided to run the factory setup (stock as a rock) as I knew this would allow me to get where i wanted to be asap. After looking at some of the forums and posts the arrangements of styles can very. 2) 8D's. 4-6 Group31's. 4) 6T's like factory. I used the factory setup and retained the hold down and cables ( all in good condition). If your terminals and cables are shot ,might lean you in the direction of for different batt setups. BTW if still in place, the thing in the center of the hold down (curly que wire with a wand with red LED is for testing lead acid batteries).

Advanced testing of old batteries will tell you what you need if you are trying to keep them in the equation. Snap on testers test each asspect of the battery and will give a health report.
Batteries need to have good health. If you know the history it will give you a piece of mind and will answer a lot of questions. Clean terminals and good ground at the box

The variations around the box to my understanding is related to year/ series of rig. On the right side it can have a simple plug for a slave cable to jump power to rigs. From my reading- Some will have a larger box with a battery disconnect switch on the bottom and disconnects inside?

Next up is the Junction style under the spare tire. Depending on the rig this can be a Polarity Protection Device, Brand (SURE POWER PROTECTION DEVICE) only has the 12V and 24V wires in and 12V and 24V wires out. On the output side it should reflect a Slight drop (roughly .7V) This terminal feeds to the cab main power distribution panel. PDP. Note that the PDP has a specific layout with 12V and 24V Relays and Circuit breakers. 24V relays have 5 terminals and 12V have 4? Double check the relays are appropriate for the placement. Ive seen many images where lots of them are missing on rigs. This unit has diods in it to protect against hooking up the DC voltage incorrectly.

The other style is the LBCD - (load battery control device) Brand (NEIHOFF) It has the same inputs and outputs that the PPD, but has a harness (five wires) that ties into it to manage the charge control from the Alt. based on battery voltages and charge state. It also has An LED to let say what stat it is in. (see the Neihoff links for info later)

From my readings, many have found issues here with a loose terminal, broken stud when trying to loosen the nut. Testing the voltage on the input and output side will let you know the state of the connections. and output. Then checking the voltage at the PDP, and at the ALT for both 14V and 28V.

PDP. From what ive seen the K11 is the exciter relay tied into the oil pressure signal to the ALT to rectify/energize the charging state?

NIehoff has great diag. flow charts. Once you get the numbers from your ALT/REG and what type of box under the spare tire.

At the Alt. Factory style 100Amp. You will find that you may have a variation of ALts. Neihoff N1506 with my understanding is the N3030 regulator atttached (NO LEDS) The other is the N1509 (with LEDS) which i believe is a later model that can be on earlier rigs, mine being 94 with a PPD rather that the LBCD.

ON the regulator you will find the front terminal (closet to the radiator front of engine) is the 28V signal to tell the ALt to energize (start charging) This signal voltage is sent after the oil pressure signal is satisfied at 15PSI? Main function is to allow the engine start function to complete and RPM to satisfy before full draw of the Alt can be ignited to cause a strain. AKA excessive noise belt slipping.

The key is to remove the front terminal on the Voltage Regulator and test the voltage with the engine running at the wire that feeds to the regulator. DO you have 24V? This is the Excite, Exciter wire that is mentioned so much. The wire can have many issues to why it doesnt provide the voltage to Ignite(rectify) the ALT. Some will say its designed to operate a certain way so fix it piece by piece. I can Agree with that to an extent. I feel most of our use of these trucks will be under stated for the life of the consumable parts. The Key that is mentioned so many times is an excite wire from the fuel solenoid positive. It is a keyed on signal that will tell (excite/start) the ALT to charge. Not a factory solution, but in terms of most uses will fill the needs.

If you have a runner and dont have 24V to the front terminal to the REG. it is a simple test ti excite the ALT. Easiest is the 24V from the lug at the ALT. Jump to the front lug of the REG to tell it to fire up the ALT charge circuit. Otherwise you can get 24V from the PDP, PPD, or straight form the 24v Batt signal to try to energize the charge function.

NOTICE- THE WIRE CONFIGURATION OF THE VOLT/REG.... 5 WIRE FOR EARLIER MODELS 3030. 6 WIRES ON 3207. THIS WILL BE IMPORTANT IF YOU TEST OUT FOR ALT/REG.

Alternator, Niehoff is the brand. 100amp factory. seen some 200amp from Hummers installed but requires different PDP etc.as they are rated at the factory 100amp.

Once you know your model you can search the Flow chart for diag. from Neihoff. Ive searched the site and started down a link to find it was the wrong ALT or REG. Get the numbers from the equipment on your rig.

From Niehoff's flow chart. When you get the flow chart for your model ALT. It is critical to understand the terminology of each item. Based on the images, B-....so Negative. Then B+ for 14V and 28V. The main lugs. (Note the washers between the + lugs are fusible links. Havent found much out other than that they are there.)

I started on this flow chart and had to talk a day to get in the groove.(most likely due to sitting around to long)
I found the term Connector harness/ alt. a little confusing as they dont give a description beyond that of images. One main ket is when theu mention to jump from the Alt to the B- they are talking about the ground on the alt to the chassis. Not the B- terminal of the reg., The main things to realize is in that flow chart they are talking about . There are three components when the alt to reg harness is disconnected. the B+14V ---B+28V---B- as in negative. The connection between the ALT and Reg had its own designation and purpose of the voltages. They are labeled A-E on terminals but have designations of the different positive voltages and ground. Its interesting how they list them. I messed up on one the first. It is key to recognize the diff between B- on the harness (Between the alt and reg) and B- on the ALt. A on the harness to B- AKA Ground will energize the fields creating a magnetism on the center shaft of the ALT. when you do this jump you can hod a piece of metal by the center shaft and feel it pull the it in as a magnet. Pics will help spell this out.

When testing the harness alt to reg With good batts you can do some major welding/frying of the leads from the alt. I found a wire with a butt connector was best sutied to protect shorts between lugs. ( I shorted one out and had to clean it up. wasnt pretty, much different form 12V

The main part is getting down to the main issue. So often do we find that a connection or a simple item is the Hello moment. The understanding of these ALTs being brush less and pretty stout should allow some confidence in the surrounding items.

I hope this helps. I will add images for the descriptions above, WOuld love others input as ive just dove in ready to make something happen.

Im after a N3207 Regulator if you have one

Cheers

.
Big thing to remember is that the wires that jumper from battery to battery need to be BIG FAT THICK copper wires. Cheap auto parts house wires just won't work. Or let me rephrase - they will work - but not well.

My M1088a1 had 4 perfectly good big square (factory) batteries in it. The the hoodlums decided they could remove my batteries to sell for scrap (guessing what they did with them). I replaced those with EverStart 124R (700cca) because they were available here and now.

Unfortunately, the wires I had with the "factory" batteries were too short to make the 24v jumps. They were too short to make the 12v parallel jumps too. I also thought I would be smart and get "boat terminals" so there would be a wingnut to make the connections. Bad Idea. They aren't beefy enough to get the job done.

Ultimately, big 1/0 wire and the proper battery terminals made the difference. Wire that wasn't large enough made the amp meter in my truck bounced up and down (good to not enough to good to not enough).

CLEANING the connections on the PPD was a good thing. Had nothing to do with my problem, but now the amp meter stays rock steady.

 

[Ronmar]

Yep, this alt is sensetive to what it sees on the other end of the line. If it doesn’t see a good 12-24 relationship, it will just pulse as it continually tests to see if the batteries are valid so it can charge them...

 

[JD4044M]

It used to pulse, it would jump to normal once in a while then drop back down. Going to town to get a couple new cables and 8 new Battery Clamps

 

[JD4044M]

It is so nice now Charging right and just connections causing the problems. Washed up the engine at the same time I added a extra neg cable to the frame. Added 2 new 2/0 Cables crimped them up. I will heat shrink later forgot it in town! Much more balanced putting the 12 v cable in that was missing. It was only using one battery for the 12 VDC Power needed. I still will do the 2 rear ones tomorrow. Now for my need 4 New Tire Problem!!

 

[Mullaney]

It is so nice now Charging right and just connections causing the problems. Washed up the engine at the same time I added a extra neg cable to the frame. Added 2 new 2/0 Cables crimped them up. I will heat shrink later forgot it in town! Much more balanced putting the 12 v cable in that was missing. It was only using one battery for the 12 VDC Power needed. I still will do the 2 rear ones tomorrow. Now for my need 4 New Tire Problem!!

.
Dang Right! Sure is nice when things work like you want them to...

I beat my head against a rock on my battery problem for a while.
Sure is good that good connections and cables solved your problem too!!

 

[Ronmar]

Well I wouldn’t call that right... This thing should be delivering 14.1 and 28.2V Your 12v is nearly a volt low(13.2 is a long term float voltage). Your 28v is more than a volt high, so something is outta wack... if you measure the running voltage on all 4 batteries I think you will see what I mean. 29.39 - 13.29 = 16.1... I bet the innermost batteries are seeing that remaining 16V and are going to loose their electrolyte in short order...

”Somethin still ain’t right”...

 

[JD4044M]

Well I wouldn’t call that right... This thing should be delivering 14.1 and 28.2V Your 12v is nearly a volt low(13.2 is a long term float voltage). Your 28v is more than a volt high, so something is outta wack... if you measure the running voltage on all 4 batteries I think you will see what I mean. 29.39 - 13.29 = 16.1... I bet the innermost batteries are seeing that remaining 16V and are going to loose their electrolyte in short order...

”Somethin still ain’t right”...

Yes I already measured that and was wondering myself? The rear 2 are both at or near 15 volts. They are getting higher volt charge rate. One nice thing is my Transmission Low Voltage Code D-1 = "13" cleared itself when the voltage went up. Bet the Speedometer does not jump around now. I finished all the connections today with a bunch of new parts and Heat Shrink all of the new ones I made up. Going to watch it for a few days and see what rate it stays at? Going to be dealing with new tires soon. Need to get the truck up in the air and ready to go. What could cause the un/even voltage?

 

[JD4044M]

OK I will measure the voltage now that I am done (I hope) with this part. Forgot to write it down so I have the right numbers to look at. Thanks for all the help.

 

[Ronmar]

OK I will measure the voltage now that I am done (I hope) with this part. Forgot to write it down so I have the right numbers to look at. Thanks for all the help.

you could have a battery that is breaking down with current applied and loading the system Beyond limits. Since the 12v is low, I would suspect one of the outer 0-12v batteries. I would start by disconnecting 2 batteries at a time, one inner and one outer(Like opposite corners). And see what it does with just a pair of batteries in the circuit. You can do this easily by just lifting the battery connections off of the battery and setting a piece of wood in there to hold them up off of the terminals, then start the truck and measure. Shutdown, reconnect the first two, Disconnect the opposite two and re-test.

looking at your latest pic, i noticed something. The two ground terminals closest to the camera are tied together(circled in red) but are the two 24V terminals closest to the frame tied together(Red Circle and ? Mark)?

They should be tied together also. Of the two 24v leads, one of those leads goes to the starter and one goes to the alt and PDP. this would make the 12v bank look twice as big as the 24v from the alternators point of view, and could cause some imbalance like you are seeing... it is also reducing the power available to the starter by 25%?

i will recommend to you like I recommend to everyone, drop to just 2 batteries. Way less connections, less stuff to go wrong, but still plenty of power to start the truck... The alternator will thank you for taking that monster bank off the line

 

[JD4044M]

Did a test tonight and came up with this while engine was OFF with charged batteries the front two are 12.59 VDC and Rear 2 are 12.78 VDC adding up to 25.32 VDC total. Then started engine Voltage Front 2 was 13.53 and Rear 2 are 14.19 for 27.58 VDC Total Charging.

Tested it under Load with every thing I could turn on ON! Heater Fan, Flashers, Headlights, Brites, Radio ETC. That dropped Voltage at the batteries some. Front 2 was 12.46 VDC and Rear 2 was 12.57 VDC. Voltage 25.75 VDC Total. Ran it under full electrical load for a while. Shut the Loads off Batteries jumped back up to Front 13.30 VDC and Rear 2 was 13.28 VDC Voltage was 26.61 total. So seems like it adjust to the load go up when needed just does not stay on a high charge rate all the time? Do these numbers look better now that I though I was done with this part?

Yes the Batteries are tied together at the far end you just can't see the cable.

 

[JD4044M]

I was going to go to only 2 batteries and save the other 2 for Jump Reasons if needed. They would stay charged but not used unless needed. Just Isolated Charged Spares inside the Box

 

[Ronmar]

The alt doesn’t know nothing about charge rate. Simple straight voltage regulation 14.1/28.2v. it should deliver this rain or shine, all day long regardless of load changes until the load is so great that it cannot maintain voltage and the voltage starts to fall away from that regulated voltage. Or if the alt has an issue and cannot make rated output under normal loads...

have you measured the voltage at the alt after all these changes/cleanings?

in your cleanings did you happen to clean the connections on the polarity box? The cbles between alt and batt are not home runs. there are two separate cables for each voltage(alt to polarity and polarity to battery), and they are joined at the polarity box input terminals. That is where the lines to the cab PDP branch off. It is located just inboard from the spare tire, and is easiest to access by lowering the spare and kneeling in where the tire sets. Because of it’s location it is also out in the weather, so they are probably nasty.

Mine were, shortly after I got mine, I went to start it one day and it went click click click in rapid succession. The dirty connections at the polarity box finally went bad and the voltage at the PDP was dropping so low when I pushed the button(pulled current) that the control relays were de-energizing/re-energizing as the voltage jumped all over the place...