bluebird71

iTrader: (54)

Since I had the auto swapped in back in '09, my main brake lights will only work about 30% of the time. I tried putting in a new brake pedal switch and adjusted it, but it didn't fix the problem. The 3rd brake light work just fine, but the main 2 will only come on randomly when they feel like it (very rarely though). Everytime I screw with the wires and get them too work, they will always go back out in a day or so. There is obviously a short somewhere, but where do I start looking? Is there something in the auto harness that the main brake lights go through that the 3rd doesn't that I need to check? Is there a common short out spot on the rear wiring that may have just popped up coincidentally? I have no idea how they tie in from the pedal all the way to the lights themselves. I really hate electrical bugs!

wssix99

iTrader: (5)

Check the ground screw just insde of the hatch behind the cover material. It's the only shared component between the lights.

bluebird71

iTrader: (54)

The grounds in the back look good and tight. I replaced the switch in the floor and the 3rd brake light works just fine. If there was something wrong with something in the switch or around that area, could the 3rd brake light still come on? There are a bunch of crazy spliced wires under there console cover by the shifter from when they swapped in the auto. Could sonething there be the problem?

wssix99

iTrader: (5)

Since you turn signals don't work, I'd expect it's a problem at shared components. The entire rear harness unplugs a few nches forward of the ground screw. You can probe the connector at that point and confim if the problem is in the forward part of the car in the back.

puddingmmmmmmmm

iTrader: (3)

No the third eye brake switch would not work if the brake light switch wasn't working properly.

bluebird71

iTrader: (54)

No, the turn signals DO work. The rear lights also come on with the headlights and as I said before, the 3rd brake light works all the time. There is a short somewhere that isn't letting the main brake lights come on when they need to. Is there some wires that go through the auto shifter that also control the brake lights, kinda like the reverse lights (which work fine by the way)?

wrencher

iTrader: (2)

3rd stop is wired seprate.
It's the turn signal switch, doesn't matter if the signals work.
The T/S switch has to complete the path to the rear lower lights signal off.
Search here others had the same issue.

bluebird71

iTrader: (54)

I have considered that it could be the TS switch, but this problem occurred after the auto was swapped in so it has to be something that would have been changed or altered in that swap.

wssix99

iTrader: (5)

The turn signal switch connector is under the dash at the base of the steering column. Its real easy to test there and will confirm if the switch is good.

bluebird71

iTrader: (54)

How do I test there? Do I need a volt meter or something?

wssix99

iTrader: (5)

You'll need a voltmeter set to 12V to probe the wires. If you ground one wire to the body and then probe with the positive test lead, you should see 12V when you press the brakes at the connector point where a white wire from the switch connects to a light blue wire going to the rest of the car. This is the brake signal wire from the pedal.

If you are getting 12V at that point, next probe the yellow and dark green wires with the turn signal off/neutral. These return the brake signal to the back lights.

If you have voltage at the white/light blue junction and nothing at the yellow and dark green wires, you probably have a bad turn signal switch.