My right brake light works all running lights work turn signals work even third brake light works but left brake light does not . I have replaced bulbs wirinf is still in factory casing any help would be greatfull. Sorry everyone it's a 1999 monte carlo z34 have replaced brake light switch still not working I will try the turn signal switch. Thankyou everyone! !! :-)45

 

ok, might be helpful if you post the year of your car, thanks and welcome to the forum.....

 

you replaced the bulbs and did you replace the fuse? year would be helpful also i had a 97 Grand am gt that had the same prblem and i had replaced the bulbs an fuse so i took out the tail light case only to find it was filled with water. dumped it out let everything dry and it worked fine.

 

If it's a '95-'99, the multifunction (turn signal) switch is probably going bad

 

Sorry everyone it a 1999 Z34

 

Does the left brake light not work at all? Have someone step on the brake pedal and see if it lights up in the back.

I had this problem recently where mine right one wasn't lighting up like normal only when i pressed the brake it would come on. The thing i did was pump the brake a few times in park then flip the turn signal switch back forth a few times and seems to be working now like normal. Dont know if that a solution or maybe its dumb luck that it started working again like normal other wise you might be looking at replacing turn signal switch. i have a 99z34 as well.

 

As it has been said, Turn signal switch. I opted to take this one to the mechanic. Looks like a real SOB of a job. I think the part retails for like 50-70$.