[Mook]

69 GTO, at times my high beams work most of the time they don't. New front wiring harness. Turn on high beams and all the headlights go out, interior light have a pulse with sound. Hi-Beams have a tiny illumination. The three wires from the switch become very warm to the touch. So I bought a new switch plugged it up and at first nothing worked, then I turned headlights off and one and everything worked. One day later right back to old no lights mode. I began to look for a short, could not find one. The three wires gong to the switch looked wrong by the book. Tan should be in the middle, blue to the right and green to the left. On mine blue was in the middle the tan was right and the green was on the right and the blue was on the left. Switched them hi-beams did not work but there was no hot wires and no pulse. I took fuse box off the wall under the dash, no short but I found a yellow wire that had been cut, have power with key on. Can anyone please tell me where that wire goes and or what it does?

1. I would love to figure out what the issue is with the hi-beams.

2. What the heck is that switched yellow wire is for and what should I do with it?

As always thanks.........

[Mook]

Ok been tracing wires, when switched on the light green wire at the dimmer becomes very hot and I can hear clicking sound from the headlight switch. I tried several other used headlight switches and several dimmer switches (new including one from NAPA).

I am guessing that the green wire is grounding somewhere creating resistance, thus becoming hot?

Could there be another approach or theory I should be considering?

[LPete]

The blue wire is the feed from the headlight switch, and should be in the middle of the connector. The tan wire feeds the low beams, and green is the high beams.

It sounds like the green wire is shorted to ground somewhere between the dimmer switch and the headlights. The clicking in the headlight switch is the built-in circuit breaker -- without that you would have melted your green wire.

I suggest putting a lamp (a headlamp works well, but a turn signal bulb would, too) in series between a battery source and the wire you're testing. The lamp will glow brightly when the wire is shorted to ground, and go dim when the short is removed. This lets you move along the harness while you wiggle wires and see if you can locate the problem. If that doesn't work you start disconnecting any connectors in the circuit to try to isolate it. Disconnecting the bulkhead connector would tell you if it's behind or in front of the firewall.

[Mook]

Thanks so much LPete, I will start working on that tomorrow!

[LASJayhawk]

Yellow is usually power to the radio.

[Mook]

Originally Posted by LASJayhawk

Yellow is usually power to the radio.

I was thinking but I found a yellow wire that looks to run into the wire harness under the dash that someone had spliced to a thick pink wire from the fuse box. I'm going to attempt to trace the spliced wire to see where it goes......thanks

[Mook]

After all of that....the next days the fuse for the back-lights/interior lights kept blowing....did some looking and found this....... I had run the harness in a bad area where the wires would get pinched between the hideaway buckets and the front of the car..... when I would sit in ten driveway with a slight hill the bucket would pull away from the front of the car....on flat surface the bucket would retract and rub......5+ hours how much that would have cost at a shop???? All is well now......for now