M931a2...new battery switch in dash, still no movement on gauges

[tactical45]

I had to switch the main battery on switch back and forth half a dozen times to get the gauges to move (or the truck to crank) a few weeks ago.

I figured that the battery switch on the dash was the problem so I ordered a new one from Boyce and installed it. Unfortunately nothing happens when I switch the battery switch on with the new switch either.

What do I check next?

 

[zxmedic]

Check your electronic control box
I had a very similar event happen with my 813. Changed the control box everything worked.

 

[rhurey]

I doubt that switch controls all the power, it's got to feed a relay somewhere. (I can hear it clicking when I flick it) Look for it in the TM's.

 

[thenext44]

I had similar problem with no power, at first I could switch the power switch on and off bunch of times and it would come on, then one day it was dead no matter how many times I tried. In the beginning I could hear clicking coming from the Power Control Box on drivers side firewall. Opened cover and found lower solenoid looked like ****, and burnt off ground wire. Thread is here.

 

[tactical45]

Thanks guys, I'll check out your thread, sounds very similar to my experience.

 

[Floridianson]

Got the same problem. This is why it is a good idea to carrie a remote starter button in the truck when out and about and a must for any tool box.

 

[wheelspinner]

The PCB grounds THROUGH the mounting bolts and studs on the lower right (facing it) corner. The ABS also grounds here. Take the bolt and spacers out and make SURE you have a clean surface all the way to metal. I have checked three, all had paint on the spacer, and one was showing signs of failure, and one had failed. Lack of ground is the killer of parts like these boxes.