Read Defroster and Third brake light.

[SilverFire]

Ok guys I'm not gonna be like everyone and say that my third brake light wont come on, however its the other way arounds. Sometimes when i turn on the rear defroster the light comes on inside and my third brake light comes on outside. Sometimes when i hit my brakes the indicator light inside for the defroster will come on. Isnt it supposed to be 2 seperate circuits or is it one?

[Rob Bell]

Re: Read Defroster and Third brake light.

I think you have a bad ground, probably between the hatch and the body. I would first suggest cleaning the ground side of the defroster grid. The connection is right on the window. If that does not work, then I would suggest checking the ground where the hatch meets the body. I'm assuming this is a wire and not the hinges. Maybe others on here will know where that connection is.

You could also test the bad-ground theory by jumping a wire (same size as the defroster wire or bigger) from the defroster connection to a good ground spot on the car. If your problems stop you found the culprit. So then, if you cannot find the bad ground between the hatch and body, you can discreetly run the new ground wire to fix it.

Bad grounds are notorious for causing those strange things you see like lights lighting up. I had a bad ground in my driver side low-beam headlight and it was causing all four headlights to light up, but they were only half brightness. I ran a new ground wire and it's been fine since.