Batteries wired up 24v in series

[Whitfield]

Drove 50 miles to look at a M1008 this morning. Some one had stolen and cut the batteries out of it. The owner rewired it up best he could but wired it up straight 24v connecting one battery to the other in series.

He said currently he could jump start it but it would not start on it's own and that he was having charging troubles (alt light on). Since wiring it up straight 24v he has not used the truck for anything (no registration no insurance) but has driven it around his property on occasion.

I'm a cucv newby but have been reading everything I can get my hands on. If I were to bring this truck home what electrical grimlins might I find from the 24v trauma.

 

[gungearz]

Have any pictures of under the hood...?

 

[Whitfield]

I was there with cell and camera and didn't take any .

Lead from front of front battery is going down to starter. Rear lead of front battery connects to front of rear battery. Rear of rear battery connects to ground boss on fire wall.

I do not yet have my head wrapped around how the truck switches the the circuits to make 12 and 24. But I do not believe 12 is possible with the batteries wired in this configuration.

 

[M923driver]

Sounds like it is possible that one or both alternators are not wired into the system, which would explain the chaqrging issue. Hard to say what damage is done if there is 24 v in the 12 v circuits. Bulbs and motors (fan, wiper) won't like it too much, relays will tolerate it for a while if they're momentary, and the GP's won't like if if the resistor is by-passed. The starter is meant to be 24 v, so you won't have a problem there. Fuses and/or fusible links may have saved you as well. There's no computer or any real electronics to speak of, so I doubt that it is a huge mess. Get it wired up correctly and assess from there. Good Luck!

 

[doghead]

There are schematics in the rear of the -20 and -34 TMs.

Each 12 volt alternator charges a 12 volt battery. The batteries are wired in series. There is a 12v connection between the two batteries(drawing off the front battery) for all the 12volt items of the truck.

 

[Whitfield]

Thanks,
I'll dig thru the schematics later this evening and reassess.

Ideally I'll go back down and wire it up correctly (older gentleman and a friend of my brother-in-law). Then take it from there ~

 

[dmilkman589]

http://www.steelsoldiers.com/cucv/75505-cucv-wiring-diagram-color-except-m1010.html