New Truck - Need Wiring Assistance

[Kjenavy]

I'm having trouble on my m1008 it has a battery shut off switch that doesn't work. Going to remove it tomorrow. But the small ground wire from the front battery to the frame was melted in two. Any thoughts why?

 

[cpf240]

I'm having trouble on my m1008 it has a battery shut off switch that doesn't work. Going to remove it tomorrow. But the small ground wire from the front battery to the frame was melted in two. Any thoughts why?

My guess would be a bad ground somewhere else in the system, causing that one to handle most/all of the load. I'd start with checking the ground connections to the engine.

 

[Kjenavy]

Ok thanks. There's a battery shut off switch in the cab that doesn't function. The ground front the front battery runs to it via a thick battery cable and gets grounded to the frame via a 16ga wire. If i remove the switch where should the ground run?

 

[Warthog]

Please download the FREE technical manuals for your vehicle. The wiring diagrams are in the appendix of the TM 9-2320-289-20 or the TM 9-2320-289-34 manual.

You will also need to read the first few pages of Chapter 2 - Troubleshooting in either of the above manuals to help you understand how to read the diagrams and to learn how to read the wiring labels.

http://www.steelsoldiers.com/showthread.php?77609-TM-s-for-the-CUCV

The cuttoff switch is not stock and it sounds like the previous owner (fire department) had no clue on how to wire it.

Because of the 12v/24v wiring system in the CUCVs, some though needs to take place when working on the battery wiring.

I am attaching a diagram from the tech manual that shows how a stock system is wired.

Before you start messing with anything you need to tell us about your truck. Is it still 24v? Does it have two alternators? Does it look like any additional wiring has been hacked? The above information DOES make a difference on how we help you fix your truck.

 

[Kjenavy]

It is 24v still. 2 alternators. I'm not seeing a ground strap from the engine to the frame. I'll be going through the grounds this afternoon. Would anyone have a picture of the ground from the engine to the frame. It's 30 degrees out but am determined to get this fixed today. Thanks

 

[Warthog]

Here is a list of all the ground location. A lot of good info in the CUCV Helpful Threads sticky.

http://www.steelsoldiers.com/showthread.php?120289-CUCV-Electrical-Ground-Locations

On a stock system the main ground comes off the front battery and goes to the bottom terminal block behind the rear battery. It then goes to the frame.

All ground connections need to be clean and tight. Many members will add additional grounds.

I also moved your posts to your own thread. That way we can help you work thru the issues with your truck.