No, it's not the bulb!

My '66 coupe has a problem. The passenger brake light and turn signal will not work. The blinker flashes at normal speed, which makes me think the old wiring may have worn through some where and grounded out. I replaced the turn signal switch a few years ago with one of the high quality [/sarchasm] repro peices. The under-dash connector seems fragile.

Any ideas on where to look or other troubleshooting tips? I need to get the car tagged by 10/15/08 or I will lose my plates.

TIA!

 

Seems like a good time to get down into the wiring and sort it out. Wish I could direct you to a normal faulty area but I wouldnt know. I'd check the flasher, all connections....maybe have to pull the cluster for easier access.

Possibly disconnect your batt and use a meter to check for continuity on your wires one by one. Hard to say without seeing it in person.

 

i'd replace the bulb first and check for the connectors in the housing. maybe they were dodgy or the bulb was. since they use the same ground as for the tail light the ground seems to be fine. So I'd check on the wiring next. It's "green-orange" and "orange-blue". They're both going directly to the turn signal switch.
Maybe a coninuity test will help here

 

Thanks guys! Finding the cause will be my project for this weekend. I meant to add that the parking lights work on both sides, just not the brighter brake/blinker filament. I've swapped bulbs, and the problem persists. I'd drive the car alot more if I could figure this out. Now that I've got our S197 Mustang set up the way I like it, I can use that mod money to fix/repair/replace the things on my '66 that I've been meaning to do.

 

I just spent 2 weeks under the dash of my 66 for a similar reason. Turns out the electrical connector that attaches the positive wire to the brake light switch was cracked and missing a retainer thing. Connected the wire directly and it worked.

Now I have to stand on the brake pedal real hard (replaced the brake light switch) don't know how to make this work with a softer touch on the brake.

Get a little ($10) probe that lights a small light when power is flowing. Go to the brake light switch and verify you have power going and coming fromthe switch.

 

Using the exterior light schematic that JamesW posted in his FAQ, I was able to trace the wiring. I had always thought that the turn signal switch was my culprit, because the 6-prong connector seemed to be fragile. Looking at the schematic, I realized that the rear lights don't run through that connector - the two wires have their own 2-prong connector. So I unplugged that and used my circuit tester to check each wire with the blinker on. The driver's side lit up first, then I tried the other wires and when I turned that blinker on the circuit tester also lit up. Hmmmm, so it wasn't the switches (brake pedal or turn signal). I figured the problem was at the back, but when I went to plug that connector back together, I noticed that it was all gooped up with some kind of lubricant. The connector was gross! So I used a little gun degreaser (RemAction Cleaner) on the connector. Guess what? It now works! The connector was all mucked up (literally). Funny how the simple things can cause such a hassle.

I appreciate the tips here - they helped my pin down the problem and get the car fully operational again. I'll be driving to DMV tomorrow to get the tags renewed. Thanks again!

BillHop

 

Now that my lights are working, I ran my coupe through DMV today and got her tagged for 2 years. Now I can drive the car again 'til the weather turns nasty. Thanks again for the help guys.

 

If only they all were this easy.