[Solved!] Heated Mirrors Dead, Rear Defroster Working

[NeilDiamndTriCoat]

Hello - I'm very new here, but for the life of me I couldn't find a thread regarding this.

My 2015 Yukon SLT's side mirrors are not heating. Neither one of them. However, the rear window defogger is. When I popped off the driver side mirror, everything looks normal and the pins for heating were not broken.

Has anyone else experienced this? Is there a fuse I should look for? I can understand one mirror not heating, but both?

Any and all help is appreciated! Thank you!

 

[Fless]

Download your owner's manual from the GMC site and use it.

 

[NeilDiamndTriCoat]

Download your owner's manual from the GMC site and use it.

View attachment 478859

Hot damn! Thank you! Going to go check this right now.

 

[NeilDiamndTriCoat]

"Download your owner's manual from the GMC site and use it."

I just went back there and this is what I have, slightly different? There are no teeth for the fuse to grab in space 4? On my sticker in my glove box I do show DL3, which I understood is heated mirrors. The mirrors do have blind spot detection, turn signals, and power folding.

Thank you.

 

[NeilDiamndTriCoat]

I found out my owners manual shows spot three for heated mirrors, and the fuse looks good, but they are still not warming up.

Any other thoughts?

[EDIT] It was actually this website that shows it, the GMC Manual page shows the spot that @Fless showed me. Fuse Panel

 

[Fless]

That web site shows the relay for the mirror heat is in the lower lefthand corner (19-2). But it doesn't look like your fusebox has that. This is a 2015 shorty, or an XL? Not sure if that matters.

 

[Bagherra]

Looking at those fuse locations, why dont i see a fuse for the power windows?

 

[Doubeleive]

the fuses and relays are REALLY screwy on the k2's I would look at the gm upfitter guide for more detailed accuracy
not only are they screwy they use all different sizes and type of fuses. micro, mini, standard, 3 leg, you name it... it's kind of bizzare to be honest.
I sometimes look at mine and go WTF was some engineer thinking

 

[Fless]

Might not hurt to verify all of the fuses in that fusebox.

 

[Doubeleive]

Might not hurt to verify all of the fuses in that fusebox.

I was going to say the same
all you need to do is touch the outer metal contacts with your meter probe, you don't have to physically remove each fuse.

 

[RST Dana]

Check for voltage and ground on the wires on the back of the mirror with the heat function active. Could be the mirror.

 

[Doubeleive]

Check for voltage and ground on the wires on the back of the mirror with the heat function active. Could be the mirror.

the chances of both mirrors being internally defective is pretty slim, I have never seen one or heard of even one going bad, if it was the rear glass that's a different story

 

[Fless]

Note that the fusebox diagrams for the Denali differ from non-Denali; make sure you have the correct book.

 

[RST Dana]

the chances of both mirrors being internally defective is pretty slim, I have never seen one or heard of even one going bad, if it was the rear glass that's a different story

I had one go bad. It might be easier to test both for power/ground that to look for fuses/relays in the haystack of electronics.

 

[Doubeleive]

I had one go bad. It might be easier to test both for power/ground that to look for fuses/relays in the haystack of electronics.

ya they should have around 5v when activated, they should have continuity also.

 

[NeilDiamndTriCoat]

Very concerning that I’m missing that relay in the back? The 19-2? I can’t tell if it has teeth or not to receive/hold the relay. Photo attached.

I have a voltmeter and its current set to DC. When I touch the black and red to each fuse, it beeps. Am I doing that part right?

When testing the mirrors, do I test with the rear defroster on? Do I touch the pins to the female wire connectors or male part that is in the mirror?

 

[NeilDiamndTriCoat]

Solved! Turns out the relayfor heated mirrors (8430/13500113) was missing. Popped a new one in from Amazon and they heated right up!

 

[Fless]

Makes one wonder why it was missing. BOLO for parasitic draw?

 

[NeilDiamndTriCoat]

Yeah, that is concerning.

Is there a way to measure that somewhere? Other than waiting for the car not to start?

 

[Fless]

Look up YouTube videos on measuring parasitic draw.