Electrical Help Please

[m38inmaine]

I am repairing a few units just received by the forest service. The oil pressure, voltmeter and water temp gages are fluttering back and forth, not working at all or sometimes working. I have not taken the gage panel off yet but looking for advice on the problem such as a ground for the gage panel perhaps.
Also since it has been a long time since messing around with these at initial startup the electrical system is surging on/off for about a minute or so. I am guessing it's the glow plug control but want to make sure.
They have gotton 4 so far and are in pretty nice shape, just trying to get them working correctly for fire season.

Thanks

 

[goldneagle]

First thing I would suggest is check the GROUND wire going from the gauges. It may need cleaning where it grounds to the chassis.

 

[emmado22]

Define surging... Thats normal depending on the severity of it for the voltmeter...

Check the grounds.............

 

[nk14zp]

Start with the grounds. If you need a hand PM me.

 

[Ferroequinologist]

I would bet its a ground issue

 

[camogriz]

Ditto on the ground issue. Check the ground straps from engine to frame and frame to body. Broken ground straps wreak havoc on electrical systems, making them act strangely and the problems will occur inconsistently. I recently had an inoperative fuel gauge and discovered that the electrical connection for the instrument cluster was loose (just a sidebar). As far as the surging, my M1009 does the same thing you describe upon startup. I've had mine nearly three years and it's always been that way, for me it appears normal. Good luck.

 

[actionpaintball]

X5 ground issue. Run an auxiliary ground wire kit (or make your own).

 

[tanhmmwv]

buy the grounding harness.... mounts on the L side rear of the engine block, then, 1 wire to the generator, 1 wire to the PCB, 1 wire to the starter, 1 wire to the body. it will eliminate allot of headaches.

 

[yamabro]

I agree or you could ohm check it to see if you have a good con.

 

[Katahdin]

My 93' GMC does something like that when the battery terminal ends work their way loose.

It actually broke me down at a gas station in Sherman, ME (225 miles from home) after leaving Baxter State Park. A local came over and knew exactly what the problem was, I bought the guy a 12 pack of beer.