I had a problem show up on my 1960 1/2t. When I first started driving it,all my lights worked normally as expected.It passed state inspection. Some time later,I noticed my tail lights worked as parking lamps, but went out when the headlights were turned on.
Being smart like I am, I looked at the wiring diagram and concluded that the only way this could happen had to be the result of a contact failure inside the light switch. No big problem, I ordered and replaced the light switch. Guess what.. I still had the same problem.
I could see no way to fix the problem other than to add a 12v relay by tapping into wiring under the dash. I wired the relay to energize from the light switch feed to the dimmer switch, applying power to the single wire feeding both tail lights. I still have no idea what happened to cause the problem.
meansam
