2008 Denali Driver's Tail Light

[StuckinMN]

2008 Yukon Denali.
Driver's side tail light works for turn signal, hazard, open door with remote, etc.

But when I have the lights switched on (set at auto, running or just on) it does not illuminate.

I pulled (and switched for good measure) the tail light fuses to no avail. (25, 26 and 27)

** Last month I tried to rent a trailer but when they hooked it up one of the turn signals didn't work on the trailer (tired another trailer just to be sure). Not sure if it is related. I did find a brake fuse that was out today but don't have a trailer to test if that was the problem.

** When I purchased the beast the turn signal stalk was bad. The previous owner had purchased one but was unsuccessful in replacing it. I put it in and all seemed to work fine but I didn't check tail light - just signals. Not sure if it is related.

Help. Out of ideas : )

 

[StuckinMN]

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[B-train]

It may seem dumb to ask, but did you check the bulbs or to see if there is power on the running light socket? There are 3 bulbs inside if I remember right- 2 large and one small. The Hazzard and turn are a different bulb from running lights I believe. It's been awhile since I had mine out to do work on, but if needed, I can pull out and investigate further.

 

[StuckinMN]

This is a Denali so it has the Cadillac LED bank. The LEDs light up for other functions - just not for light switch.

 

[Geotrash]

This is a Denali so it has the Cadillac LED bank. The LEDs light up for other functions - just not for light switch.

Cadillac LED bank...where? Your taillights should be regular incandescent bulbs.

 

[StuckinMN]

So I switched tail light assemblies and the assembly worked fine on the passenger side. So it is something with the relays, fuses, switches or wiring.

Any ideas?

I checked the fuses and they are good. I don't see relays for the tail lights listed anywhere.

My neighbor mechanic suggested could be the light switch itself (he works on European cars).

I see many people with the exact same issue but no solution listed : (

FYI: Yukon Denali's have LED tail lights like Caddies. It is essentially an Escalade.

 

[StuckinMN]

I just tested the relays and made sure the fuse had power. All good.

So next I will check the light switch itself.

 

[wjburken]

FYI: Yukon Denali's have LED tail lights like Caddies. It is essentially an Escalade.

I have owned a total of 3 Yukon XL Denali's (2007, 2008 and now a 2013) and none of them have had LED taillights. If the previous owner made a change, that is a whole other thing, but from the factory, they are not LED on the Denali's

 

[Geotrash]

I have owned a total of 3 Yukon XL Denali's (2007, 2008 and now a 2013) and none of them have had LED taillights. If the previous owner made a change, that is a whole other thing, but from the factory, they are not LED on the Denali's

+1. If you have LED tail lights on your Denali, then it's aftermarket. I own two Yukon XL Denali's - a '07 and a '12 and they both have incandescent bulbs in the taillights.

I haven't seen where you've said that you tested for power and ground at the taillight connectors. Can I assume that you have done so, and that you have power and ground continuity there? If so, then the taillight assembly is the only possible culprit.

 

[StuckinMN]

+1. If you have LED tail lights on your Denali, then it's aftermarket. I own two Yukon XL Denali's - a '07 and a '12 and they both have incandescent bulbs in the taillights.

I haven't seen where you've said that you tested for power and ground at the taillight connectors. Can I assume that you have done so, and that you have power and ground continuity there? If so, then the taillight assembly is the only possible culprit.

As posted above, I tested by switching assemblies.