Re: Peculiar problem on 1934 1103

Posted by Tim Cole On 2012/8/13 17:05:58

Dear Traum:

I think a good place to start is by dividing the circuit.

To do that remove both tail light bulbs, turn on the park lights and check the source voltage with a test light. If both pins have voltage then you have a harness problem.

Move on to the backup light switch and brake light switch. Check both for voltage before and after the switch. If the test light indicates voltage on both sides, disconnect the wires and check for voltage. If you have voltage on both sides then you have a harness problem. Otherwise test the switch for a closed circuit.

Move up to the headlight switch. Isolate the park light post and check for voltage. Disconnect the wire and check the brake lights. If everything is haywire then look for a harness problem.

Grounds are easy to check. Make up a long jumper wire and run it from the battery ground post. With the park lights on use a voltmeter check the voltage between the ground post and the lamp socket base (ground). If you have more than .4 volts (.2 ideally) you have a ground problem.

Finally, with the lights on get under the car and wiggle the wires from front to back. If the lights start flickering then you have found the harness problem. Tip: Put a stand up mirror in your line of vision the shows the action at the back of the car.

As well consider a disconnect switch if not already installed. If the car manages to catch fire it will burn to a cinder.