Help diagnose this tail light/blinker problem, please...

[KMeloney]

Hey all,

Here's the deal: Started to get a fast-blink on my LEFT LED tail lately. At this point, it fast-blinks every time I use the left signal. I swapped my Denali tails in in the meantime -- and I STILL got the fast blink (left only) with them in.

Upon swapping my LEDs back in, I've noticed that the reverse light does not light in the left housing. Also, when I unlock the vehicle with the remote, where the brake lights and reverse light would normally illuminate, NO LIGHTS in the left LED tail light. Oddly enough, the brake lights illuminate under normal brake application, and the standard (non-braking conditions) lights work under normal circumstances, too.

So, in a nutshell, regarding the left LED tail lighting:

- No reverse light, ever
- tail lights light fine when lights are on
- Brake lights light fine when brake is pressed
- NO lights light when brake/reverse lights should come on upon remote unlocking
- Lights light, but blink fast, when left turn signal used

What has me a little concerned is that I got a fast blink with the stock Denali housings in there. (What I didn't do is diagnose the circumstances of the range of lighting of the Denali lights...)

Does this sound like just the reverse bulb is out (and maybe out on the Denali light, too), or does it sound like a bigger [wiring] problem?

Thanks!

-Kirk

 

[KMeloney]

Ok...

I just swapped my TAHOE oem lights back in, and with them in, everything is working fine.

So... I think I have either a wiring issue to the LED's backup light AND a bulb problem in my Denali oem lights.... Or, I have no idea what could be the problem.

I'll take any thoughts on the matter. I'll keep the factory Tahoe lights in for the moment until I can get this figured out. Thanks!

 

[scott_white85]

Water in rear doors is common - Rain water inside rear doors! - remove the rubber thingies Fast flashing indicators usually indicates that one of the bulbs have gone - check the front and rear indicators are working correctly (put on the hazards to do this).

 

[youknowmyname67]

if you have only tried the bulbs try replacing the board.... I went through it with my yukon where some bulbs would work and others wouldnt but it ultimately ended up being the board the lights go in. i cant remember the name of the board but its the actual housing the lights go into....i found it was the board on mine when i was changing the lights with it on i was holding the board a little tight and everything was flashing like it was a cop car. the board costs me $7 hope it helps or is atleast in the same ballpark.