Brake Light issues on a 72 Road Runner

[RRGTX72]

Okay here is another problem I have just encountered. My brake lights stay on regardless if the pedal is pushed or not. I have ruled out the brake light switch by checking it with a light. When the brake pedal is pushed it gets power to both sides of the switch. When the pedal is not pushed it only has power on the one side. I know it is a short, but I just don't know where to begin. I have noticed that when I take the dome light switch out on the driver's side, I lose the brake lights. Any help would be greatly appreciated.

 

[70rr-brian]

EDIT....

Pink wire is hot? White is not? White runs to turn signal switch (switch possibly bad) Trace brown wire from turn signal switch to 6 pronge connecter? Check connector for any visable damage. From there to a 4 pronge connector (inspect for damage) Or at least that how it seems to me... see links:

http://www.mymopar.com/downloads/1972/72CoronetChargerA.JPG
http://www.mymopar.com/downloads/1972/72CoronetChargerB.JPG

 

[72 Charger SE]

3- Not 100% sure about any of that...but it is also possible that the wiring for the brake switch is run through the turn signal switch as well....which could also be the problem.

Yes, the brake lights run through the turn signal switch. Turn signals and 4 way flashers use the same wire to the rear of the car to operate the brake lights/turn signals (2nd filament of the double filament bulb.)

I haven't seen one go bad this way, but I suppose it's possible. I've had to replace 3 turn signal switches over the years when my brake lights and turn signals stopped working at the same time, once in my Charger and twice in the 70 Challenger I used to have.

 

[tpodwdog]

before you go ripping that car apart. check the grounds. make sure ya have good grounds....if not....the power will go looking for one.! good luck !

 

[RRGTX72]

I just replaced the hazard and turn signal relays, is it possible that if I am not using the correct ones that it would causes this problem? Also for the ground issue, I have 3 black ground wires that come from behind the dash that I have grounded to a screw on the back side of the dash. How is the best way to check the ground? Where else should I be looking for grounds? Thanks everyone for their inputs and please keep them coming. I will keep you guys posted on the progress.

 

[moparmarks]

Theres a ground jumper at the column mount. Check for that. The flashers should be a #552 two post.
The EM flasher switch may be the problem. It transfers the brake lights from the brake light circuit to the EM flasher curcuit.

 

[70rr-brian]

I just replaced the hazard and turn signal relays, is it possible that if I am not using the correct ones that it would causes this problem? Also for the ground issue, I have 3 black ground wires that come from behind the dash that I have grounded to a screw on the back side of the dash. How is the best way to check the ground? Where else should I be looking for grounds? Thanks everyone for their inputs and please keep them coming. I will keep you guys posted on the progress.

Well that's an interesting nugget of info. I assume the old ones were just bad? Try another one if you have any and see if it goes away.

Also, whenever you are talking about grounds for anything tail lights you need to find the ground in the trunk. Should be easy to find....just look for the wire going to the body somewhere near the tail light assembly. Usually around the trunk latch area.

 

[moparmarks]

Here is the rear body harness ground. In the trunk on the drivers side.

 

[RRGTX72]

Should both the flasher and EM flasher be a 552? I cleaned the ground in the trunk area yesterday when I had it all apart, but will ensure it is getting a good connection. Will also check the other grounds.

 

[moparmarks]

Yes 552 for both flashers.

 

[RRGTX72]

Thanks everyone for their inputs and directions. I finally found the culprit. It only took a few minutes of wire chasing under the dash to find it. When I was hooking everything back up after paint and wiring the steering column wires up, I must have been color blind that day. I had the yellow wire going to the brake light switch and the white wire that was supose to be going to the brake light switch going to a yellow wire. Leave it to the rookie to not know his colors. Again huge thanks to everyone that got me to that point of chasing wires.:icon_super: