When your turn signal stays on when you are not turning it off, it is probably a sign of a malfunctioning switch. The problem usually starts with the switch below your steering wheel, which is designed to control the blinking of the front and rear turn signals. If it fails, the signal will remain on and draw power from your battery even after you switch off your car. This article discusses how to check for and repair this problem in a few different ways, including replacing the switch assembly.
Question: I have a 2008 Suburban 5.3 4wd and the right front and rear turn signal will not stay off even when turned off, but other functions like radio, clock and remote door locks work fine. I pulled all sorts of fuses, but nothing seemed to stop the lights from staying on. What do you think the problem is?
Answer: It could be any number of things. It might be that the switch below your steering wheel has gone bad, or it could be a problem with the bulb itself or the socket. There could also be a problem with the ground wire for that side of the car, especially if it was damaged in an accident or in some other way.
In any case, it is worth checking the switch, the bulb and socket, as well as the body control modules and relays to see if they are the cause of this problem. Then, you can decide how to go about getting this fixed.