Strange electrical shorts on first trip

[tturner]

First time post. I just bought a 6.2 powered '83 Class C motorhome. On the drive home, I noticed the volt meter was fluctuating. Then I noticed the glow plug light was coming on. Every eight seconds, the dash indicator would light up and the volts would drop. Slowly but surely, the battery seemed to be drained as the glow plugs pulled more power than the alternator could produce.

Then, the windshield wiper started running, even though the switch was OFF. Whenever the glow plug indicator would go off, the wipers would move a little.

I had to get home so I just kept going. The sun went down and at first I only ran the parking lights. My brother, driving behind me, said the lights would dim whenever the glow plugs would be activated. Finally, when the voltage was down around 8 or so, the glow plugs and wipers quit firing up. Then, the "Fasten Seat Belt" light came on! I barely had enough juice in the headlights to make it home.

I plan on installing a manual Ford relay for the glow plugs but it is apparent there are some serious wiring issues. Any ideas? I have some manuals on order and will start studying the wiring diagram.

Through it all, the engine ran fine.

[Dvldog8793]

Howdy and welcome!

Without knowing more about the system in your motorhome and how it was put together....I would say to start looking for a short to ground in a main power wire from the fuse block or whatever the company used for a glow controller could also be shorting and activating the other devices.

Since the glow circuit was the first thing you noticed I would start by backtracking the trigger wire on that circuit.

Good luck....!

[Robyn]

Grounds

This sounds like a classic ground issue, as in POOR GROUND SOMEWHERE.

A bad ground on a circuit can cause all manners of hinky things to happen.

Start with the battery grounds to the engine and to the chassis.

Keep us posted

Missy

[tturner]

Thanks for the tips. RV manufacturers are known to do some crazy things with the wiring systems on Class A's. Hopefully, this Class C still has the factory wiring for the engine. Time to look for ground issues.