What is wrong with my tail lights?

Question

2000 Saturn LS2. Tail lights work fine when headlights are off, so the bulbs are OK. Tail lights work fine when headlights are on, too, except for when I step on the brake. At that point, the tail lights go off, instead of getting brighter. The middle rear-view window brake light works fine.

How can I fix this?

Answer 1

Both tail lights on the LS2 have a single ground.

Sounds like it has come loose.
I know because I just replicated the problem in the garage. with a 2001

Pull the liner and look at the wiring for the tail lights. follow each wire until you find the one that goes to the frame or body. Look on the drivers side...

Answer 2

I've seen situations like this many times. Usually it is caused by a shorted (not necessarily blown) bulb. Two weeks ago we had a Camry in my shop where the lights were doing all sorts of bizarre things - if you pressed on the brake the dash lights would go out for example. After my mechanic wasted about a half-hour checked wiring diagrams I finally convinced him to just start pulling bulbs.

2 were blown, another worked but the two electrical contacts at the base had melted and fuzed together, shorting the circuit and another bulb, a dual-element tail/brake light bulb had blown one element and one filiment had fallen onto the other, causing that circuit to short. 4 new bulbs later and everything worked perfectly.

So in short, check ALL of the rear BULBS FIRST (including the center brake light bulbs). A shorted bulb is far more likely than shorted wiring.

Answer 3

Probably 98% of the time, what you describe is happening because the ground is bad. Tighten up the screw or bolt that holds the light socket to the vehicle if there is one. If not look for a wire that comes off the socket and goes to a screw in the metal, and tighten it. You can check it by running a jumper wire from the socket base to a known good ground and see if that fixes the problem. I'd bet it will.

Answer 4

Sounds like some wiring is crossed/grounded, take out the bulbs and cennectors and see if there are any breaks in the wires or if anything is loose or touching..

if one light is doing than it could be the bulb socket, if they both do it than the brake light switch (by the brake pedal) is either faulty or has a wiring issue..

Answer 5

sounds like a short or wiring problem, unless you have alot of experience with electrical things I'd take it to a mechanic, electrical problems are really tricky. I'd check the fuse too, that's probably not it since they work sometimes but when electrical problems occur it never hurts to check that it's a easy cheap fix.

Answer 6

it could be a short in the wiring or it could be a fuse blown.