Hmmwv no power to alternator

[Lazboytt]

Hello wondering if anyone knows if there is a Fuse-able link between the starter and alternator.
I have power at starter and half way up the wire on the motor to the alternator but no power to the alternator. Wondering if there is a fuse able link in the wire loom before I cut it up to look for it
6.5na with 200 amp alternator

Basically I went to start it up and realized I didn’t wait for glow plug light to finish so I let the key go, next I had no power at all when turning the key. Not sure if someone could have spliced the wire somewhere or a fuse able link went bad.

I did change the intake housing and the wire runs behind it so I could have either damaged the fuseable link or perhaps the wire.

Any ideas

Sent from my iPhone using Tapatalk

 

[BLK HMMWV]

Well from your drawing you linked to both here and on the G.503 board it plainly shows the word fuse stud on the Alternator were the big black line goes to the starter.
Might want to try there.

 

[Lazboytt]

From the diagram the fuse looks to be on the alternator but wondering if it may be mid way as I have power in the wire where it comes up from the bottom but after it goes around the intake before the alternator it looses power. Was wondering if it could be a bad wire or if fuse is mid way. Was hoping someone may have ran into the same issue and may know before I start to cut open all the sheathing on the wires


Sent from my iPhone using Tapatalk

 

[Lazboytt]

So the schematic is incorrect. The wire goes from the alternator to the glow plugs start box. Looks like I have a short wire that’s right at the plug that goes into the box.


Sent from my iPhone using Tapatalk

 

[Retiredwarhorses]

You haven’t said want Generator you have, but 60amp charges through the EESS box.
when you stop getting charge at the batteries but output at the Gen, it’s generally the back gone bad with burnt wiring internally.

 

[papakb]

6.5na with 200 amp alternator

Power runs directly from the alternator output connection to the starter. Disconnect your batteries and check for continuity on that cable.

You have the 200 amp dual voltage alternator. With some really nasty wiring! Disconnect your batteries and clean up all of the connections then use some dielectric grease to keep them from corroding again.

 

[Lazboytt]

Here is what someone else said in another form which I just found out. Now I need to confirm if I have a 200 amp or a 60 amp alternator I know someone change the motor

In vehicles with the 60 amp alternators there is an 8 gauge wire (5A) that runs from the alternator output stud to the control box and then to the starter. Because of the higher current output from the larger alternators that line runs directly to the starter stud and then to the batteries. When you do the 200 amp conversion one of the first things you do is to install that larger cable between the alternator and the starter. If your truck was retrofitted with the 200 amp alternator and the conversion was done half-assed whomever did it may not have removed the wire to the control box it could still be there but if it is you need to remove it. The original purpose for that was so that if the batteries were installed backwards the PCB would prevent power from turning on and damaging the rest of the electrical system but running the full 200 amps thru the control box would have meant another redesign and significantly larger connectors.

My suggestion would be to disconnect the batteries and remove the wire from the alternator output and the starter and see if it hasn't opened up somewhere.


Here are pictures of my alternator also if you happen to know if that would be the 200 amp I thought it was because of the size but I could be wrong

Sent from my iPhone using Tapatalk

 

[Retiredwarhorses]

That’s a 100/200 setup,you should have output of 28.5 at the positive output stud of the generator, no output?
Bad regulator most likely.

 

[Milcommoguy]

At the 24 volt stud of the 200 amp alternator... you will always have battery voltage. With a working (running engine) alternator charging, a regulating voltage will be present. (increase to nominal 28.5 VDC+/-)

It's a direct connection to battery in this configuration, CAMO

 

[Lazboytt]

That’s a 100/200 setup,you should have output of 28.5 at the positive output stud of the generator, no output?
Bad regulator most likely.

Retired Warhorse I now have power I just wiggled some wires at the plug that goes into the glow plug control box. With that alternator should the battery cable come directly from the starter since it’s a 100 200 amp or should it go from the starter to the box to the alternator as it currently is? If it should go direct should I just splice the wire and bypass the controller box?


Sent from my iPhone using Tapatalk

 

[papakb]

You quoted me from the G503 reply and I answered this question for you. Yes, the 60 amp output goes thru the PCB on the 5A wire and with the 200A setup it goes directly from the alternator to the starter. Think of how large the connector pins on the PCB connector would need to be to reliably handle 200 amps.

If your wiggling wires and things start working you either have wiring that's corroded or getting ready to break or connector pins in bad shape. Remember, anytime you connect or disconnect the control box you want to have the batteries disconnected.

 

[Milcommoguy]

Lazboytt, Clean up that nasty ground lug, under the ground lug on the front of the alternator, your third picture. Better yet, clean them all up.

Don't forget to disconnect batteries and get back in formation, CAMO

 

[Retiredwarhorses]

Your regulator is installed backwards...the 14v tap should be pointed forward, your data plate will read upside down to you when installed correctly. Your cannon plugs ar wrong as well from what I can see Because the regulator is backwards.

 

[Retiredwarhorses]

Your regulator is installed backwards...the 14v tap should be pointed forward, your data plate will read upside down to you when installed correctly. Your cannon plugs ar wrong as well from what I can see Because the regulator is backwards.

On second thought...that is an early 100/200, so it may be correct, I can’t tell from the pics.
it would be wrong for a current 200amp setup. I need to look in the shop, I think I have an early one like that.

 

[Mogman]

The original charge wire (5A I believe) coming from the EESS is used on the 200A conversion to excite the alternator so you for sure do not want to remove it.
If the alternator is a 200A and is not charging check to make sure there is 24V at the large output stud and if it does make sure there is 24V going to the IGN terminal on the alt to excite it, if not it could be a bad EESS

 

[86humv]

Info :

 

[Mogman]

What is shown in the fist image at the top is 568 being cut (you can see the X on it) and what you don't see is 5A (just out side of view) also connected to the IGN. terminal, this is as the conversion instructions that came with the conversion kit say to do.
568 is the original IGN. lead for the 60A alternator and is too small to carry the exciter current needed for the 200A alternator.

EDIT
As the instructions say 568 is disconnected and is "plugged" and tied back to the harness (starting with line H) and shown in the first illustration, then connecting 5A, which was the output line on the 60A to the IGN. terminal (second illustration)
On the two EESS boxes I have opened up 568 and 5A are simply tied together inside so the EESS excites the alternator at the same time it connects the 60A output to the battery making them virtually the same circuit, only 5A is much larger, so it would probably work using 568 but the voltage drop due to the extra current required for the 200A alt. might cause some gremlins.

I believe the illustrations directly above are mislabeled, it is plain to see the wire labeled 568 is a large wire and not representative of the actual 568 lead, in fact it shows to be the same size as the 14V charge lead going to the batteries.

 

[John Perry]

That’s a 100/200 setup,you should have output of 28.5 at the positive output stud of the generator, no output?
Bad regulator most likely.

What Milcommoguy said contradicts what I see on my M998. "
At the 24 volt stud of the 200 amp alternator... you will always have battery voltage. With a working (running engine) alternator charging, a regulating voltage will be present. (increase to nominal 28.5 VDC+/-)
It's a direct connection to battery in this configuration, CAMO "
I have an issue with that statement he made. NOT the case with my M998.
My parts, 100 amp dual voltage Alternator 12447110, NSN 2920-01-407-3532. Voltage regulator is a dual voltage 3135. Controll box is a NARTRON 12469158-1 ( have 3 of them here). Already modified the glow plug wiring as to be able to manually control the application of voltage to them as needed, bypassing the control box. I am a aircraft Avionics Tech, have knowledge about how "Trons" move about.

On my M998 I have never seen any 24 volts measured on that terminal on the Alternator when the engine is not running as Milcommoguy stated.
My issues started slow then advanced rapidly to a no Alternator output at all. Additionally the heater blower motor would not turn on when the alternator was not putting out, even though the volt meter was reading at the top of the yellow range, but below the green. At the voltage reglator I had measured 2.4 VDC on the IGN terminal wire, at the wire connector, open and not connected to the regulator. With that wire connected to the regulator, zero volts. I jumped in a wire to put 24 volts to the IGN terminal, and the Alternator is working, good output from the Alternator now. Questions are,,, I have read that the 24V terminal on the Alternator is directly connected to the battery wire at the starter motor, as in the above drawing, apparently not in my case, not connected until the Alternator is putting out voltage. How does it connect when the Alternator is putting out voltage? Where does the 24 volt excitation power for the IGN terminal come from when the starter switch is in the RUN position? Does the power come from the control box or the starter switch? Where does the wire numbered 568 in the above drawing connect to ???

 

[Milcommoguy]

What Milcommoguy said contradicts what I see on my M998. "
At the 24 volt stud of the 200 amp alternator... you will always have battery voltage. With a working (running engine) alternator charging, a regulating voltage will be present. (increase to nominal 28.5 VDC+/-)
It's a direct connection to battery in this configuration, CAMO "
I have an issue with that statement he made. NOT the case with my M998.
My parts, 100 amp dual voltage Alternator 12447110, NSN 2920-01-407-3532. Voltage regulator is a dual voltage 3135. Controll box is a NARTRON 12469158-1 ( have 3 of them here). Already modified the glow plug wiring as to be able to manually control the application of voltage to them as needed, bypassing the control box. I am a aircraft Avionics Tech, have knowledge about how "Trons" move about.

On my M998 I have never seen any 24 volts measured on that terminal on the Alternator when the engine is not running as Milcommoguy stated.
My issues started slow then advanced rapidly to a no Alternator output at all. Additionally the heater blower motor would not turn on when the alternator was not putting out, even though the volt meter was reading at the top of the yellow range, but below the green. At the voltage reglator I had measured 2.4 VDC on the IGN terminal wire, at the wire connector, open and not connected to the regulator. With that wire connected to the regulator, zero volts. I jumped in a wire to put 24 volts to the IGN terminal, and the Alternator is working, good output from the Alternator now. Questions are,,, I have read that the 24V terminal on the Alternator is directly connected to the battery wire at the starter motor, as in the above drawing, apparently not in my case, not connected until the Alternator is putting out voltage. How does it connect when the Alternator is putting out voltage? Where does the 24 volt excitation power for the IGN terminal come from when the starter switch is in the RUN position? Does the power come from the control box or the starter switch? Where does the wire numbered 568 in the above drawing connect to ???

2 1/2 years later and getting thrown under the bus. Then why post the same thing I was saying. Sorry couldn't answer all your questions. Mogman is likely correct your 100 amp unit was hacked in and control box is not going to be happy. And for a first post... sound like you have it all figured out.

Covid is a real thing, CAMO

 

[Mogman]

What Milcommoguy said contradicts what I see on my M998. "
At the 24 volt stud of the 200 amp alternator... you will always have battery voltage. With a working (running engine) alternator charging, a regulating voltage will be present. (increase to nominal 28.5 VDC+/-)
It's a direct connection to battery in this configuration, CAMO "
I have an issue with that statement he made. NOT the case with my M998.
My parts, 100 amp dual voltage Alternator 12447110, NSN 2920-01-407-3532. Voltage regulator is a dual voltage 3135. Controll box is a NARTRON 12469158-1 ( have 3 of them here). Already modified the glow plug wiring as to be able to manually control the application of voltage to them as needed, bypassing the control box. I am a aircraft Avionics Tech, have knowledge about how "Trons" move about.

On my M998 I have never seen any 24 volts measured on that terminal on the Alternator when the engine is not running as Milcommoguy stated.
My issues started slow then advanced rapidly to a no Alternator output at all. Additionally the heater blower motor would not turn on when the alternator was not putting out, even though the volt meter was reading at the top of the yellow range, but below the green. At the voltage reglator I had measured 2.4 VDC on the IGN terminal wire, at the wire connector, open and not connected to the regulator. With that wire connected to the regulator, zero volts. I jumped in a wire to put 24 volts to the IGN terminal, and the Alternator is working, good output from the Alternator now. Questions are,,, I have read that the 24V terminal on the Alternator is directly connected to the battery wire at the starter motor, as in the above drawing, apparently not in my case, not connected until the Alternator is putting out voltage. How does it connect when the Alternator is putting out voltage? Where does the 24 volt excitation power for the IGN terminal come from when the starter switch is in the RUN position? Does the power come from the control box or the starter switch? Where does the wire numbered 568 in the above drawing connect to ???

The 60A alternators output went through a start box relay so there was no voltage on the output terminal unless the vehicle was in the run position.
When it was converted to 100A there should have been a large wire run directly from the alternator output terminal to the batteries, the start box relay cannot handle the output from a 100 or 200A alternator.
Your truck seems to be using the old 60A charge wire (5A) which is incorrect.