When I had the Notchback painted, the third brake light was disconnected in order to remove the spoiler.

Since I put the spoiler back on, the third brake light hasn't worked.

I got out my multimeter, and (as long as I'm using it right ... I'm kind of an idiot when it comes to those things) with the brake pedal depressed, I have 12 volts at the contacts inside the trunk, I have 12 volts in the wires where they come out of the hatch with the hatch down (so it's making good contact between the contacts inside the trunk and the contacts on the hatch), and I have 12 volts at the bulb sockets ... so I have power EVERYWHERE it needs to be.

But then when I install the (brand new) bulbs, they don't work. Not only that, but with the bulbs in I can't get my meter to register any power at the bulb sockets! WTF??!!

I have taken the piece out that the bulbs pop into and cleaned it thoroughly with steel wool, as well as the ends of the bulbs themselves.

I have NO idea why putting a bulb in the socket seems to kill power to the socket.

Here is how I have my meter set (sorry for the fuzziness ... the dial is pointing to "50":



And here is how the meter is reading with the bulbs OUT. This reading is taken at the positive end of one of the bulb sockets and the negative end of the other bulb socket. The needle is sitting just above 12v:



And here is the type of bulb that my third brake light takes:



Any ideas what's going on?

*Edit - I think it might be the ground. If I ground the meter's negative lead on the hatch lock cylinder, I get a reading with the bulbs installed. I'll post up if I figure it out.

**Edit #2 ... I traced the ground and checked it ... seems to be OK ... ???

***Edit #3 - Here is a rough paint drawing of the sockets where the bulbs pop in. It's a little hard to tell red from black in this drawing, but I think you'll get it.

 

Here is an idea: Measure the ground at the socket to the bulb. Do this by finding a good measured ground by 12 V power and metal ground or wire ground somewhere else close by. Then check ground by the resistance on the meter: Measure ohms ground to the negative on the socket. You will find no ground probably. Or zero resistance if it is grounded. You want zero resistance. Then you have a good ground and should have power for the bulb. Check for corrosion at the wire ground to the third brake lite.

 

Thanks, but I need that in simpleton terms. You lost me.

 

OK. I'm officially an idiot.

I checked for resistance. 0 ohms.

WHY ISN'T THIS WORKING!!??

Well, I tried to pull one of the bulbs out and it lit!

They pulled the bulbs out of the sockets when they painted, and I guess it "bent" the sockets a little. I pinched them down with some needlenose pliers and ... tada!!

Thanks!

 

Cool good looking car, by the way. I Have an 89 TA. I like the front clip better, but you have the better car. I Had a 91 Firebird with the little V6 and the same front clip. I really enjoyed the T-tops. How do you like the convertible? I know my firebird was red and attracted a lot of attention. Im sure yours does too. Where are you from, anyway?

 

Thanks for the compliments! The car in my sig is my '92 convertible. The car I'm working on is an '88 Notchback. I agree that I like the nose on the 85-90s best. But a red convertible with tan interior does get a LOT of attention. Too bad I'm old and married now ... I would have killed for this car in high school .