# 66 GTO Blinker/Brake Light problem



## Indecision (Oct 24, 2010)

This may or may not be related to the whole problem, but my front left turn signal shorted out or something a while back. I noticed the bulb was out, replaced it, was burned out very shortly after. Haven't chased the culprit of that yet...

Current bigger problem, NONE of my turn signals or brake lights are working. The tail lights work, but not the brake lights. Seeing as on this vehicle the turn signals and brake lights are the same bulbs, I'm guessing that the turn signal flasher may control everything. That or there's a HUGE coincidence that the brake lights and turn signals failed around the same time. 

So the real question is, does the turn signal flasher control the brake lights? 

If so, I have to imagine it has failed. Is this something I can get at any NAPA type place? I have heard some things need to be found at restoration type place for correct functionality.


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## 05GTO (Oct 6, 2004)

The brake lights and the flasher use the same fuse but the wires split at the fuse panel. The turn signal wire goes directly to the flasher and then feeds the turn signal circuit in the steering column. The brake lights also feed into the steering column after going thru the stop light switch.

First check the fuse, if the fuse is good then check to see if the voltage is passing thru the steering column. In the drivers floor at the firewall there should be a ribbon cable that feeds the rear tail and brake light circuit. Unplug the ribbon cable and check the voltage on the Dark green and yellow wires coming from the firewall area when the brakes are activated.

If there is no voltage the problem may be in the steering column, if voltage is present check for voltage in the trunk. If you have voltage in the trunk then check for grounding problems. The bulb sockets are grounded on the tail light housing.


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## Indecision (Oct 24, 2010)

Great info, thanks. It's not just the tail lights though, even my FR turn signal is out. I'm guessing it's the fuse. I honestly haven't even located the fuses in this car yet. I see a Painless wiring harness in my future.


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## BearGFR (Aug 25, 2008)

Indecision said:


> Great info, thanks. It's not just the tail lights though, even my FR turn signal is out. I'm guessing it's the fuse. I honestly haven't even located the fuses in this car yet. I see a Painless wiring harness in my future.


Depending on the overall condition of your car, replacing the entire harness could be like swatting a fly with a nuclear warhead....

Fuse panel should be on the drivers side of the firewall, under the dash, just above your left foot.

Things to check:
Fuse
Flasher
All the bulbs, front and rear
shorts in all the bulb sockets
"wiggle" all the wiring harness connectors to the steering column, and/or 
disconnect them and clean all the contacts with a pencil eraser.

If you don't have some sort of multimeter, get one. They aren't that expensive.
I've got one of these:
Innova/Auto-Ranging digital multimeter (3320) | Multimeter | AutoZone.com

Bear


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## Indecision (Oct 24, 2010)

BearGFR said:


> Depending on the overall condition of your car, replacing the entire harness could be like swatting a fly with a nuclear warhead....
> 
> Fuse panel should be on the drivers side of the firewall, under the dash, just above your left foot.
> 
> ...


:rofl: at the nuclear weapon comment. I wasn't going to do it just because of this issue. Though i will say.... Overkill is Underrated. The wiring is all just old as hell and I'd like the piece of mind that comes with stuff like that. There have been a few times i've almost had wires catch fire on other cars because of shoddy workmanship, don't want deal with that again.

I'm going to try to fix this tomorrow. Like I said, it started out with the front left flasher not flashing. Both of the parking lights work in front and the tail lights work in the rear. It's just the high level, so the turn signals and the brake lights. I do have a multimeter. I just posted this so i would have some understanding of the wiring before I started chasing stuff. I can spin wrenches all day, but wiring tries my patience for some reason.


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## Indecision (Oct 24, 2010)

The fuse is good, put in a new flasher, and checked every connection I could find. They still aren't working. There is a pretty scary rat's nest under the dash and I'm not really excited about trying to find the issue.


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## Indecision (Oct 24, 2010)

Messed with it some more today, voltage across the fuse is good, going to continue chasing the voltage as 05GTO recommended. All of the bulbs sockets are ridiculously corroded though, as in most of the bulbs can't even physically be removed from the sockets corroded. I'm going to order some new sockets and chase the voltage as 05 GTO recommended. 

Any other recommendations?


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## Eric Animal (Oct 28, 2007)

Check the grounds, as Randy suggested...Very important, as they are the other half of the circuit. Also the brake light switch. on the brake pedal arm is an easy check also. It is a plunger switch...Eric


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## Indecision (Oct 24, 2010)

Eric Animal said:


> Check the grounds, as Randy suggested...Very important, as they are the other half of the circuit. Also the brake light switch. on the brake pedal arm is an easy check also. It is a plunger switch...Eric


I don't think it's the grounds because the tail lights and parking lights work up front. It's just the turn signals and brake lights that aren't working, and they are grounded at the same place. As I stated, I'm going to replace all of the sockets anyway, they are ridiculously corroded and may be causing a short. Plus, I can't even get most of the bulbs out to clean the sockets.

On a slightly related note, is it possible to buy the base that the front signals mount on, or do you have buy the whole grill? I'm not seeing just the base on OPGI, but I'm still looking.


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## Indecision (Oct 24, 2010)

So, I am an idiot. While I did do a visual check of the fuse, which is 30A so it should be obvious it's gone bad, I didn't do a continuity check with my multimeter. Needless to say, there is no continuity. So I'm gonna pick up a new fuse at NAPA today and hope for the best. I'm still going to replace all of the sockets, because I believe that the corrosion is where the short is happening.


Looks fine to me, haha.


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## pontiac (Mar 6, 2011)

wrong fuse, should not be 30A on turn \ brake lights. problem is turn signal switch.


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## Indecision (Oct 24, 2010)

pontiac said:


> wrong fuse, should not be 30A on turn \ brake lights. problem is turn signal switch.


Thanks for the input. Though it's possible that it "should not be 30A," considering the fuse was labeled "turn signal/stop light" I was confident I had the right one. Also, after replacing it, the turn signals and brake lights started working, which confirmed the labeling was correct. It is possible that the turn signal switch may be what's causing the short though.

As I stated before, I'm going to replace all of the light sockets on the car in hopes that the short is located in them and go from there.


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## bigrc2 (Mar 28, 2009)

Clean your grounds! I just went through this with my 69! It was amazing the wierd things the lights were doing just because of a little carbon build up on the ground connections!


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## trialsmm (Jan 6, 2011)

Same thing happened to me, fuse was not blown, just came apart inside the fuse. It looked good but was intermitently making contact, crazy. Also you need to remove the fuse block from the firewall. On the back side are several connections. These connections were corroded on my '66 GTO. Cleaned and all is working great.
Buy the way, now I'm chasing a problem, right rear turn signal out and brake light. No power on green wire from steering colume. Will get back on it tonight,,,,,,,,,,,,,


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