Intermittent lights

Replaced the breaker today with a new one from NAPA ($6.00), tested, same result. Working on performing Walt's test...results to follow...

 

Hang in there. This is the fun of owning a 49 year old rig.

 

Isolated things a bit more. The yellow wire that connects to the switch is the problem. I disconnected wires until I found a configuration that did not trip the breaker. Without the yellow wire connected the front parking lights (switch position one) and the front headlights (switch position two) work. When the yellow wire is then connected the breaker trips. It appears the yellow wire controls the rear lights (parking and driving).


What are some suggestions to find the problem with the yellow wire?

 

Examine the wires to the rear lights and the lights themselves? Replace the yellow wire?

 

Inspect for any place it, or the wires it feeds, may be damaged and shorting to ground.

Or test them with a ohm-meter (after removing bulbs). Then if the resistance to ground is less than infinite in any wire, that is where the short is.

 

Many times PO's will add trailer lighting wires that take a real beating and are not properly installed or properly protected. If you have such a thing, I would start there. If you don't then it will be a single wire visual process. (Follow the yellow brick road)

 

will do

 

Well I found the problem. Taking Walt's advice, I inspected all the rear wiring (lights and trailer). It was a bit of a mess, lots of extra wires, wire nuts, electrical tape etc. It looks like a four wire bundle travels to the rear of the vehicle which seems fine, but it has been spliced into with wires going every which way. I traced it out and cut out all the extra stuff.

All lights and signals are now working in all switch positions, with one small exception. When the parking lights or head lights are turned on, and the left turn signal is on, only the white license plate light under the left red LED light flashes, not the red LED itself. The light is on, but does not flash. The left rear signal works fine when parking lights or head lights are not on.

 

You have queer electrons floating around so it sounds like the circuit has lost ground and it is back-feeding. The Tail/stop/turn light gets it's ground through the mounting studs to the tub. Un-bolt the light unit and clean the two studs, tub holes and washer/nut assy. Clean the tub around the mounting studs and re-assemble. This may not fix it but needs to be done anyway to assure a good ground for further tests if needed.