M1008 charging issue

[travis8352]

so today i started my m1008 after letting it sit for 2 months and after i drove it around the yard for a while and shut it off i went to restart it and it started up again and i let it idle for a while and shut it off, tried to restart it again and it would barely turn over. batteries were all reading 12.1 volts. after throwing it on the charger for a few minutes it fired right up and while running the front battery was at 12.3 volts and the rear battery was at 12.1 volts. both GEN 1 and GEN 2 lights are ON while the truck is running. so can anyone tell me what my issue is?

 

[Freeland]

Know anyone around there with a battery load tester? If you can get your hands on a battery load tester check each battery with the truck running, and without the truck running. Load testing each battery with the engine off will tell you the condition of each battery, and load testing each battery with the engine running will tell you the condition of each alternator.

 

[travis8352]

not sure ill have to look into it. im going to be replacing the batteries with some nice 1000 cca batteries soon.

 

[Tinstar]

Battery's aren't getting charged.
New ones will do same until you fix the charging issue.

Two months?
If all was good when you parked it, I would start looking for signs of mice eating your wiring.

If no sign of that then start your troubleshooting

Need some back history about the truck before you parked it.
Rumning well or not ?
lights on then or not ?
12v conversion?
etc.

Thats my thinking anyway

Someone with way more knowledge than me about these will chime in soon.

 

[travis8352]

Battery's aren't getting charged.
New ones will do same until you fix the charging issue.

Two months?
If all was good when you parked it, I would start looking for signs of mice eating your wiring.

If no sign of that then start your troubleshooting

Need some back history about the truck before you parked it.
Rumning well or not ?
lights on then or not ?
12v conversion?
etc.

Thats my thinking anyway

Someone with way more knowledge than me about these will chime in soon.

the alternators were not charging when i parked it either. its had this issue since i bought it in september 2015. i just parked it for the winter and then when i started it up and drove it around and shut it off and tried restarting it and it barely would crank over i knew i had to fix the issue.

truck runs great

if im remembering correcvtly the lights have been on since i bought it. their dimly lit to so idk if that means something or not. no 12v conversion either.

 

[cucvrus]

I think possible bad alternators. If the Gen 1 and Gen 2 lights are on dimly you could have a bad fusible or a bad diode in the alternators. Slipping squealing belts. Any multitude of issues. I would see if you have anyone local is familiar with this truck and charging system. check the voltage where it is coming out of the alternators and repost your readings. Also have the batteries loaded tested and charged real good and load tested again. Make sure you have good clean battery cable clamps and the connections are good. I see many battery clamps that are over tightened and not making good contact from being stretched out over the years from abuse and over tightening. Post a few nice close ups of the wiring on the fire wall, batteries, and alternators.

 

[Tinstar]

I agree with CUCVRUS

Make sure you charge the batteries. Do not leave them in a discharged state.

If you have a multimeter, start with testing the alternators.
That will show what direction you need to go with the troubleshooting.