Electrical question

NCWayne · Oct 31, 2012

Having some electrical issues with the running lights on a late 80's L8000 Ford dump truck. It took me several hours this evening but I at least managed to find and fix several shorts, and at least get the lights working if I bypass the relay. The way it was the owner had put several self tapping screws through the wiring harness, there were a couple of bare/abraded wires on the dump bed, etc, etc. My problem now is when I turn on the switch the clearance lights on top of the cab will light(( as they always have ))but it still won't send power to the relay that turns the rest of the running lights on. My question is does anybody have a wiring diagram, or just know where the wires go after leaving the dash switch. To be more precise do you know where the two seperate wires split/join together that send power to the two seperate parts of the clearance/running light system??? I'm planning to do some more looking tomorrow in the daylight again but thought I'd ask here and maybe save myself a little time sarching and tracing wires behind the dash.

Any help would be greatly appreciated.....Wayne

Walt Davies · Oct 31, 2012

On my l9000 truck the cab light work on the own switch and are not connected to the main switch. Other than that all I can say is that someone could have rewired yours.
Walt

MARK ROBKE · Oct 31, 2012

I, too, remember some of these having a seperate switch. I think the seperate switch only operated the cab clearance lights, and the headlight switch fed the marker/tail light relay. But, what I would probably do is ,since you can energize the relay and cause the lights to come on, is run a wire from the switch to the relay. It would be simpler and faster than finding the open. If I remember, those fords were screwy to follow the wiring.
MARK

NCWayne · Oct 31, 2012

Based on what I have read, and seen, so far the wiring on these things is supposed to be pretty screwy. I thought about running a wire straight to the relay. My concern is that because I don't know where the two parts of the circuit tie togther, I don't know where to tie in that won't keep feeding power into the broken part of the circuit even though it's actually bypassed as far as the relay is concerned.

Electrical question

NCWayne

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Walt Davies

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MARK ROBKE

Well-known Member

NCWayne

Well-known Member

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