1966 Headlight dimmer switch

[Sting Ray]

On my dads car when you hit the dimmer, the pass. lights go out and get no power to them, does this sound like the switch is bad, or is there another problem with the wiring?


Thanks,
Tom

[Firemist1]

If your term "pass. lights" are headlights, then yes, the dimmer switch is bad. There are some cheap products on the market, so be sure to get a GM switch. Could also be a bad ground or dirty contact in the lighting circuit, but the switch is the usual cause and a cheap "easter egg."

[Sting Ray]

Thanks for the reply,

Tom

[magicv8]

Both driver side and passenger side are powered by the same wire. If the wire from the LH lamp to the RH lamp has power, the lamp is fubar. If not, the problem is in the harness at the headlamps. Power comes to the LH lamp (driver's side) first, then is wired to the RH lamp from there.

[Sting Ray]

Changed the Dimmer switch and still a no-go, can the bulb be bad just on Hi-beam?


Tom

[magicv8]

If you read my last post - I told you it would not be the switch. Check lamp first, the wire second.

[Sting Ray]

Dave, I did read it and I am still confused. Since the light has Power when on regular lights, and no power to it after hitting the dimmer switch, then it is probably the light harness right?


Tom

[JohnZ]

Kick the dimmer switch to the high beam position, and check the light green wire at the dimmer switch connector for power (light green is high beams, tan is low beams). If no power there, the switch is bad (assuming you have power at the input wire from the headlight switch - light blue wire). If you have power at the dimmer connector in the light green wire, trace it through the outboard multiple connector on the engine side of the fuse block and continue forward to the connector to the headlight harness, checking for power. It's probably not a ground issue, as all four lamps share a common ground. It's probably a corroded or broken terminal in one of the connectors that feed power from the driver's side bulbs to the passenger side bulbs (assuming you've checked the bulbs themselves).

[Sting Ray]

John,


Thanks for taking the time to give me a run through of the way to check, I like automobile wiring issues about the same as household plumbing. I will go through the checklist and hope I have better luck.


Thanks again,

Tom

[Sting Ray]

Dave and John,


If I see you at Carlisle I owe you a Smoothie, the wire was broken at the drivers plug-in, both answered my question great, John just made it so I can understand .


Thanks Guys,

Tom

[JohnZ]

Glad you found the problem! See you at Carlisle - I'll be at the Vetteheads.com tent (at the bottom of the anchor line for our big red Vetteheads.com blimp) and at the Paragon/Corvette Enthusiast magazine "Rex" resurrection car display; I'll take that Smoothie!

[magicv8]

Sorry about short messages and delays. I was on vacation in FL - and it only rained 1 day - the rest were on the beach.