Posted by David on Saturday, July 07, 2007 at 15:21:04 :
In Reply to: Elect. help!!! posted by Howard in Newcastle on Saturday, July 07, 2007 at 10:44:45 :
The print is the best place to start as it will give you the basics of the wiring, but remember these trucks are very old the wiring could have been modified.
When you say you use your lighting circuit and the engine dies you probably have a ground or short in the lighting circuit as you already determined. If you trace the power wire of this circuit back to its source you could disconnect it and your truck should run. Its sounds like there is a main circuit breaker that is opening and disconnecting power to the ignition along with the lighting circuit. That may be why the truck restarts later when the breaker cools and closes. This is just my guess.
With the lighting circuit disconnected test the end of the disconnected power lead to ground and see if you have continuety, or zero resistance from the lead to the ground. If you do you will need to trace the ground systematically moving along the circuit and making disconnections to isolate areas checking as you go, until you find where the ground is located. Did I say that right?
Tracing a ground is not difficult, althought it can be very laborous at times. Others times you find it right away!