The taillights are not working after changing taillights to LEDs?

JESSIE_GEE818

MEMBER
2003 GMC YUKON
5.3L
V8
2WD
AUTOMATIC
175,000 MILES

Hello, I am having trouble with my SUV listed above lights. I recently changed my taillights from one LED to another LED taillight set. After two hours of changing them, I was told my turn signals were not working by someone behind me. I went home and tried disconnecting and reconnecting the taillights from the harness plug-ins. At this point only the hazards and the left side running lights worked. After a few more tries of disconnecting and reconnecting the lights would not do anything. I assumed it could be the fuse, so I changed them out to no avail. I went to AutoZone and bought a new flasher relay also to no avail. I’ve tried checking the harness but don’t see anything wrong with it. Any help on what it could be or what I should do next would be appreciated.

1 Reply

DANNY L

MECHANIC
5,648 POSTS

Hello, I'm Danny.

Sometimes not all led upgrades are always just plug and play. Sometimes the BCM- body control module will interpret LEDs as a bulb out. To fix your problem you might have to install resistors inline. What brand are your new LED taillights? I've attached a picture below for attention to what the resistors generally look like. Get back to us with your taillight information and we'll go from there. Hope this helps and thanks for using 2CarPros.

Image (Click to make bigger)