M1009 electrical problem

[Smokingman]

First I have done the starter relay mod, installed a new GPR109,put in new 31 series batteries(with new cables),cleaned all grounds,cleaned fuse box,new drivers side alt(passenger is charging fine) and replaced all fuses with new.The truck runs and drives well.

Now for the problems.
1.When starting the glow plug relay takes roughly 1.5-2 minutes to click,once it clicks the wait light goes out in 4-6 seconds.

2.The alternators are putting out amps,but the batteries are not charging(12.2 volts on the front battery when running 24.7 on the rear).

3.No lights.No dash,headlights,brake,or turn signals.

I need to add that the headlights will come on by turning on the black out light switch(service light) and the horn blows non stop(when the black out light is turned on).I think the horn problem is in the steering column and will take a look at that Monday.

 

[epitts]

Just a shot in the dark, look at this thread

http://www.steelsoldiers.com/cucv/65477-alternator-wire-test-trace-question.html


Good luck

 

[Smokingman]

Just a shot in the dark, look at this thread

http://www.steelsoldiers.com/cucv/65477-alternator-wire-test-trace-question.html


Good luck

Fuse is good,and the blower motor works as do the wipers.

I also have gen lights at start up,and the go out as they should.

 

[ChiefMinion]

#2) Based on the voltages you provided, it doesn't sound to me like either alternator is charging. Check out the first post in this thread:

http://www.steelsoldiers.com/cucv/54292-cucv-alternator-symptoms-diagnosis-fix.html#post623873

#3) What position is the blackout switch in?

 

[Smokingman]

#2) Based on the voltages you provided, it doesn't sound to me like either alternator is charging. Check out the first post in this thread:

http://www.steelsoldiers.com/cucv/54292-cucv-alternator-symptoms-diagnosis-fix.html#post623873

#3) What position is the blackout switch in?

Checked for charging again with the key on and off.Both are charging.The new drivers side alternator is a new Delco one(the caddy one).

#3. In the up position the horn blows,and the MAIN headlights are on(with the headlight switch pulled out,push it in and the lights go out but the horn still is blowing).With the blackout light switch in the middle position the headlights will not come on at all.

I pulled and checked fuses again since posting this.It seems that now I have no glow plugs.The light does not come on and they are not heating....sigh.

 

[Warthog]

There is a diode on the horn relay that can go bad. It isn't needed for everyday use. It is on the backside of the horn relay plug (next to the fuse box). Remove the diode and see if this issue is fixed.

The horn and headlights will not work without the b/o light switch in the service position. That is how it was designed. All of this is covered on the TM 9-2320-289-10 operators manual.

Tackle one issue at a time and you will figure it out.

 

[Smokingman]

There is a diode on the horn relay that can go bad. It isn't needed for everyday use. It is on the backside of the horn relay plug (next to the fuse box). Remove the diode and see if this issue is fixed.

The horn and headlights will not work without the b/o light switch in the service position. That is how it was designed. All of this is covered on the TM 9-2320-289-10 operators manual.

Tackle one issue at a time and you will figure it out.

Thank you I will try unhooking the horn relay.Still at a loss on the brake lights and turn signals.I did try a new relay(i had one) still nothing.It is probably something so simple it is insane.Ill keep at it.

 

[Smokingman]

Resolved a few things today.

The horn issue is fixed(thank you Warthog).

I removed the 12v bus on the firewall and cleaned it.I took some non flammable electrical cleaner to my fuse box. I used a good portion of a can with Q-tips and cleaned as much gunk out as possible with out removing the actual box.This seems to have resolved all my head light,turn signal,and brake light issues.(note I did disconnect the batteries prior to cleaning and wait for the box to dry for several hours before replacing the fuses).

Now for the glow plugs that seemed to stop working yesterday.Today after cleaning everything the wait light comes on as it should,and the plugs only took around 4 seconds to heat.There was no delay for the relay like before.No idea why anything I did would have affected this as I was only working on the 12v bus and did nothing to any part of the 24v side.

Lastly I still have the battery charge issue.The alternators are generating amps it is just not making it to the batteries.I will go through and trouble shoot the wiring Monday evening.

Thanks for all the good information everyone.Great site!

 

[Warthog]

So did you pull the diode?

On the alternators, there is a fusible link in the output line for each alternator. One at the 12v terminal block for GEN1 and one at the 24v terminal block for GEN2.

I don't have my diagrams and pictures handy but they are listed in the wiring diagrams and I have Posted pictures before. I will post them in the morning.

 

[Warthog]

The GP issue was fixed when you cleasn the 12v side of the system. The GP system is controlled with 12v and is only switching 24v.

More than likely it was the fuse that was making poor contact.

We always preach the following:

If it's rubber replace it and if it is electrical, clean it. - ralbert

 

[Warthog]

Here are some pictures of the fusible links. There are three blue ones to check.

The 12v Feed from the Negavtive terminal of the rear battery
The 12v Feed from the GEN1 (driver side alternator)
The 12v Feed TO the GEN2 ground stud (pass side)

To test the links you can give them a tug, If they stretch they are definately bad. You may need to take both ends off and check the resistance.

 

[Woodsman]

Here are some pictures of the fusible links. There are three blue ones to check.

The 12v Feed from the Negavtive terminal of the rear battery
The 12v Feed from the GEN1 (driver side alternator)
The 12v Feed TO the GEN2 ground stud (pass side)

To test the links you can give them a tug, If they stretch they are definately bad. You may need to take both ends off and check the resistance.

Warthog, looking at the schematic you posted here it appears there are 6 total fusible links in the engine compartment. With the advance of electrical gear/switches today is there an equivalent device that could be used to replace the links? The reason I ask is it possible to use a circuit breaker, which could be reset in the event it trips?

Or, is this much of an issue?

I would rather be proactive in replacing potentially troublesome known areas before it takes a dump if at all possible.

I'm trying to sort out possible upgrades to update any potential electrical issues that might be easily done and wanted to get your opinion on it.

Thanks!

 

[SGT Estum]

I would replace the fusible links with fusible links. These are designed to blow out and protect the rest of your electrical system -- which is a good thing.

All the parts are about $20-25 at NAPA. You'll just need some 12GA fusible link wire, 12-to-8GA step down butt connectors, and some heat shrink tubing.

(Double check those wire gages with the schematic; I'm running off memory here.)

 

[Warthog]

Warthog, looking at the schematic you posted here it appears there are 6 total fusible links in the engine compartment. With the advance of electrical gear/switches today is there an equivalent device that could be used to replace the links? The reason I ask is it possible to use a circuit breaker, which could be reset in the event it trips?

Or, is this much of an issue?

I would rather be proactive in replacing potentially troublesome known areas before it takes a dump if at all possible.

I'm trying to sort out possible upgrades to update any potential electrical issues that might be easily done and wanted to get your opinion on it.

Thanks!

There are more that just 6. You have to look at all the diagrams and look for the 12v and 24v links.

From another post.


Fusible links on the 24v Postive Terminal Block

3 blue – 2A – Glow Plug resistor – diagram E-7 – Gauge 12 fusible link
3 blue – 2L – Gen2 24v output - diagram E-9 Gauge 12 fusible link

1 red – 2Z – starter relay - diagram E-1 - Gauge 16 fusible link

.5 orange-101A – diagnostic system - diagram E-11 Gauge 20 fusible link (*** MISLABLED IN THE DIAGRAMS ***)
.5 orange-2K – Gen2 excitor – diagram E-9 Gauge 20 fusible link

Fusible Links for the 12v Positive Terminal Block

3 blue -2B - 12v Source - diagram E-9 - Gauge 12 fusible link
3 blue - 2H - 12v feed to GEN2 - gauge 12 fusible link
3 blue - 2M - 12v feed from GEN1 - gauge 12 fusible link
.5 orange - 2P - 12v feed to GEN1 excitor - gauge 20 fusible link

I may have missed some.

I am sure you could find a fuse panel to replace tghe fusible links. The gauge of the wire and lenght of the wire dictates how much current can be handled.

Modern vehicles have replaced alot of the fusible links with LARGE fuses.

Just depend how much $$$ you want to spend.

If a Fusible Link blows, something bigger is wrong or I have screwed something up.

 

[Smokingman]

I am now at a total loss on the batteries not charging.
Today I took it to a mechanic friend.We followed the check list to the letter.All voltages where good with the key on or off.We did some continuity testing of fusible links.Checked all grounds.Pulled the alternators and tested them.Both test at 14.7 with a load.

I have a question about the exciter wire on the drivers side.I read it did not need to be on other than initial start up(have 12v) it stays on even after the truck is running.Is this normal?

There is a black and white wire going to the ground on the drivers side alt,it is cut under the dash and taped.

With the truck running both alternators have good fields(checked with a compass).

It is like there is no load on either alternator(as tested with a load they both charged out of the truck).

Neither the front or rear batteries are charging.

In the third picture posted by Warthog there are 3 fusible links.All where cut today and replaced with straight wire.I will put fusible wire back in,but today I wanted to make sure it was not any of those links.

I need to add this.Both alternator lights come on at start up,and shut off a few seconds after the truck starts.But still.....no current to the batteries.

There is a missing wire between the ground bus and 24V bus.The suppressor wire is not there,but I was under the impression this was just a noise reduction for the military radio?

 

[Smokingman]

Still having a charging issue.
1.Today I took both alternators back off and took them to NAPA(yesterday I had taken them to Autozone).They both test perfectly.14.7V 0 problems with them.

2.Tested both exciter wires again with the key on and off.12.2V key on,0 Key off.The red wire on both alternators has battery voltage.

3.Replaced more fusible links.The only one now that is not new is the one from the passenger alternator.

4.Ran a jumper directly from the drivers side alternator to the front + terminal. There was no change in voltage.Still 12.2V

5.Pulled the glow plug card.I gained half a volt of charging 12.7 now on the front battery.

6.Unscrewed the fuse box and cleaned it as much as possible.Pulled all fuses and checked them with a fuse tester.All are good(as they should be,they are all new).

7.Unscrewed grounds cleaned and put dielectric grease on them...again.

8.Pulled off the outer dash cover and checked the wiring I could see for the bulbs.No burns or obvious damage.Cleaned and added dielectric.

The idiot lights for both alternators come on when you turn the key.They both go off when you start the truck.My volt meter is in the middle of the yellow.Voltage on the batteries is 12.7 front (after removing the glow plug card)and 12.2 on the rear battery.All lights,blower motor(at any setting),and wipers work.I have one light the drivers side turn signal that works externally,but the dash light for that side does not come on.24V at the NATO jump plug and 24V at the rear power BUS.




I am at a loss.

 

[Smokingman]

Front battery is now at 14.7 rear at 14.6.

Guess I should share how at this point.
First my front brand new 31 battery had a BAD cell.This battery was literally a week old.I have heard of it happening,but this is my first brand new bad battery.So replaced the bad battery.Still had battery voltage only.No charging.

Having gone through all fusible links and replacing them with new I knew that was not it.Had both alternators checked twice,both where good.I had cleaned all grounds.That had done nothing.

This is the point I had almost given up.I knew it had to be a grounding issue as all wiring,alternators,and batteries where good.

The fix.I ran new grounds.One off the drivers side alternator to the frame and one from the front battery to the frame.Fire up the truck and for the first time my volt meter is in the green instantly.This solved my grounding problem for around $6.00 in self tapping screws,8 gauge wire,and some 8 gauge ends.

In short if your alternators are good,your batteries are good,you have checked your grounds and still have a problem.Run new grounds to the frame.I still am not sure where my bad ground is.The starter works(so not the engine strap)and all others have been cleaned.At this point though I am just happy to have solved my little electrical problem.

 

[mistaken1]

Thank you for the after action report. Glad to hear you got it working correctly.

 

[Smokingman]

Thank you for the after action report. Glad to hear you got it working correctly.

I had to add this after reading your sig line...


Listen, strange women lyin' in ponds distributin' swords is no basis for a system of government. Supreme executive power derives from a mandate from the masses, not from some farcical aquatic ceremony.

 

[mistaken1]

LOL It's just a flesh wound.