EMKGS4

Hello everyone. New member here. I'm installing a factory third brake light under the rear glass. 1999 GS4. Car originally had factory installed wing, now gone. I've read issues with 3 out of the 5 bulbs only light up. Does anyone know why certain cars have that issue? I've read these can have wiring issues that cause this problem. Any help is much appreciated.

LexusK

iTrader: (14)

I think I had this issue when I did mine years ago. I think I just disconnected all the bulbs and then spliced in an LED strip instead.

DundukovEM

This is a fairly simple circuit with five light bulbs connected in parallel. Make sure all light bulb filaments are intact and then check the corresponding sockets for oxidation/loose connections.
Also, all light bulbs must be of the same type, otherwise current imbalances will make some of them brighter and others dimmer.

EMKGS4

Yeah I may need to take it apart. I notice the 2 bulbs that don't work have a red wire ran to them. I wondered if the lamp failure module had something to do with it. All the bulbs are the same and nothing is loose. I'll take it out and work with it again. Thanks guys.