[Brian jones]

Hi,


Things were going so well on my 64 gto Convertible project till I got to the wiring.


I have no lights to the rear, Driving lamps, brake lights or Turn signals.

Head lights and front parking lights work.

I have 6.5 volts ?????? to the brake light switch why not 12? This is with the key on only, without the key on I get no power to the brake light switch.

When I jumper in a 12 volt power source to the back of the "brake light switch" wiring connector from the harness I get brake lights and turn signals but only with the brake light switch engaged (foot on the brake).

Also,
The front turns signals will not blink wile the back ones are working using the above method.


I did a search and think it may be the turn signal switch as I see in some post it has been noted that the brake lights run through this switch?????


Thanks for any help,

Brian

[engineer]

look at the wiring diagram in you factory service manual. you will see that rear tail lights are on a different circuit than the brake and turn signals which go thru the turn signal switch. So that said, you have at least two problems to check. Start from the fuse panel and work toward the rear using the wiring diagram. Check both circuits.

[Brian jones]

Any thoughts to why I only have 6.5 volts going to the brake light switch harness / connector?

And why only with the key on? I thought brake lights work even when the key is in the off posision?

I seem to get 12 volts every ware else.

Could this be a bad voltage regulator?

[Lemans64]

Check out the wiring diagram from this website. http://www.tocmp.com/tOCMP/wiring/Po...ing/index.html
go to the bottom to 64 and check it out. did u have the dash wiring out?? need some more detail as what u had out and what u did to it. I just had all my 64 harness out last year, Non vert. Not a voltage reg problem. Also taillights don't go through turn signal switch.

Rick

[Brian jones]

The head lights switch is sticking a bit, you have to move it just in a bit after pulling it out to get the lights to come on so i new it may be bad.

After operating the switch off and on the tail lights started working again.

Still no brake lights or blinkers so i guess that means the direction switch is out??????


Thanks for the responses guys,


Brian

["QUICK-SILVER"]

You didn't say if front turn signals work. If not you need to check turn signal flasher and see if it is getting 12 volts with ignition switch on. Flasher is where turn signals get their power.

Brake switch needs 12 volts hooked up correctly and flasher needs to have 12 volts, before you can tell if turnsignal switch is bad.

Your brake light test, using brake lights to feed rear turn, does not mean turn signal switch is bad.

It would not be uncommon to have a bad turnsignal switch, you just need to make sure flasher has power, like brake lights, before you start changing parts.

[Brian jones]

Originally Posted by "QUICK-SILVER"

You didn't say if front turn signals work. If not you need to check turn signal flasher and see if it is getting 12 volts with ignition switch on. Flasher is where turn signals get their power.

Brake switch needs 12 volts hooked up correctly and flasher needs to have 12 volts, before you can tell if turnsignal switch is bad.

Your brake light test, using brake lights to feed rear turn, does not mean turn signal switch is bad.

It would not be uncommon to have a bad turnsignal switch, you just need to make sure flasher has power, like brake lights, before you start changing parts.

No the front turn signals are not working but the front parking lights do work.


I checked for 12V at the flasher with the key on and yes I do have a constant and unchanging 12V there.

When I checked for 12V at the red wire that leads into the brake light switch connecter.....at first I got 12V but then checking it again I got 6.5V and then later 4V.

After sitting a wile I had twelve volts at the red wire again but after I engage the connect with the stop light switch and press the brake pedal once the power drops off to less that 6V again.

You said above that the brake light switch had to be connected correctly. It’s a two prong connecter that could be plugged in two ways….Does it matter how you plug it in?

Also If the Directional signal switch is engaged with the key off and then you turn it on, you can hear one blink under the dash and then it stops. When this happens you do not get one flash of the lights at the rear or the front turn lights.


Thanks,

Brian

["QUICK-SILVER"]

Originally Posted by Brian jones

You said above that the brake light switch had to be connected correctly. It’s a two prong connecter that could be plugged in two ways….Does it matter how you plug it in?

Also If the Directional signal switch is engaged with the key off and then you turn it on, you can hear one blink under the dash and then it stops. When this happens you do not get one flash of the lights at the rear or the front turn lights.


Thanks,

Brian

Brian,
When I said correctly on the brake light switch, I meant get a good 12 volt power source hooked to it. Don't know whats wrong with the wire you have going to it now, would have to see the car to figure that one out. FWIW the original stop light power wire comes straight from the fuse box and should be pink. Location/position, in stop light switch, does not matter on the pink wire(power in) and natural wire (power out to column).
From what you've described, correcting that power supply will solve the brake light problem.

Turn signals; need to check the flasher out better, it may be bad and your only problem with the turn signals. Try a new flasher or put a jumper wire in place of the flasher and see if the turn signal lights light up, of course with the jumper the lights will not blink but it will tell you if that was the problem. With a jumper in place of the flasher, the purple wire in the turn signal column harness connector, should be hot with the ignition switch on.

Check it out and post back what you find, can go further from there. May end up being power supply to the fuse box.
Clay

[Brian jones]

Thanks to all you guys for the advice.

Turns out it was just a bad connection between the Flasher fuse and the fuse box connector.

Pulled the fuse, clean the connector, put fuse back in and what do you know every things works as it should.


Well at least I know the wiring diagram for the 64 Pontiac now!

The diagram at the site Rick suggested is much clearer than the one in the factory service manual. It helped printing it out on 11x17 paper and then tracing the wires out with a hi-liter pen!


Brian

[Lemans64]

Glad u got it fixed. I cleaned my entire fuse box connections before trying any electrical stuff on my ride. So ya I could see that being a problem. I was given that electrical diagram site by someone on this site. I also have a color diagram that is laminated, which makes it great for shop use without getting wrecked.

Rick