[ZeGermanHam]

Hi Folks,

I'm in the process of getting my '66 GTO roadworthy again after close to 20 years of storage. When I parked it many years ago, the passenger side brake light had not worked for a long time. The taillights and blinker worked on that side, but not the brake light. Figuring it was due to a rather cobbled together taillight wiring harness, I replaced it with a brand new harness today. As you might expect by now, it didn't fix the problem.

All bulbs are good, and we tested with a multimeter - the brake lights on that side are simply not getting juice. This me, this suggests that the issue is further upstream.

Electrical work is not my wheelhouse, so do you fine folks have any suggestions for where I might poke around next? Again, the situation is as such:

Driver side
- Taillight: OK
- Blinker: OK
- Brake light: OK

Passenger side
- Taillight: OK
- Blinker: OK
- Brake light: NOT WORKING/NO POWER

[LPete]

It almost has to be the turn signal switch. Try having someone watch the rear lights while you step on the brakes and wiggle the turn signal lever. Chances are the light will come on or flicker.

[ZeGermanHam]

Originally Posted by LPete

It almost has to be the turn signal switch. Try having someone watch the rear lights while you step on the brakes and wiggle the turn signal lever. Chances are the light will come on or flicker.

We did poke around under the dash and found a wire that appeared to be coming from the steering wheel that wasn't connected - it was part of the "curved" loom of wires on the underside of the steering column that I think is related to the turn signals. I assumed at the time that it probably wasn't the cause of our brake light problem because I didn't think that the brake lights would be affected by the turn signal wiring. But perhaps I'm wrong?

Are you suggesting that bad turn signal wiring on the steering column could be the cause of the brake light not working? It's odd, because the turn signals work just fine despite the wires on the steering column being a mess.

[boltbuster]

Give this a try? Check to see that you have good ground surface all the way around the outboard hole in the left tail light housing. The power for the brake light AND the turn signal comes through the inboard light receptacle (a dark-green wire in my 67). If there is paint or corrosion on one part of the hole, maybe it is effecting only the brake light?) Since your turn signal is getting power on that side, the brake light should also be. To be clear, I'm working from a 67 wiring diagram, but I would think that the circuits should be the same.

On the loose wire in the curved loom: if it is gray, and your trans shifter is on the floor, it is the power connection to light the selector on a column-shift automatic car.

Good luck!

[Old Goat 67]

Brake and "blink" (Turn) use same wire from turn signal switch. Dark green wire. Has be be turn signal switch.

[ZeGermanHam]

Originally Posted by Old Goat 67

Brake and "blink" (Turn) use same wire from turn signal switch. Dark green wire. Has be be turn signal switch.

Thanks for the info! This makes logical sense, so a bit of digging around the turn signal switch will prove fruitful.

[boltbuster]

Any progress on your brake-light issue?

[ZeGermanHam]

Originally Posted by boltbuster

Any progress on your brake-light issue?

Unfortunately not. My GTO is in storage far away (i.e., thousands of miles) from where live for the next six months or so. I tried to remove the steering wheel to have a peek at the turn signal switch, but hit a roadblock when I discovered that the steering wheel is supremely seized onto the column... Ran out of time and had to throw in the towel.

[johnta1]

Try a new turn signal flasher?

[george kujanski]

Second the turn signal switch.

george