What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Fless]

Fuse was missing. I replaced it but still no dice. I hear the relay kicking in and I have power through the fuse. Guess I'm gonna have to check power in the door harness at the mirror switch and compare the plug on the new mirror to the old one I saved. And check wire colors etc.

You're turning the defroster grid on, right?

 

[89Suburban]

You're turning the defroster grid on, right?

Yeah bottom button to the right of the power button on the HVAC panel.


Old mirror plug on top, new one on the bottom. Same number of wires in same positions. Colors are different, but I believe the functions are the same regardless. I test plugged in the old mirror and that won't heat up either. I opened that mirror up on the bench and did some tracing with a ohm meter. The black wires on BOTH plugs are definitely for the heated glass. I am afraid to go prodding around the door lock module with test meter probes.

 

[89Suburban]

Now that I know which wires are for the heated glass I can test them for power brb...

 

[Doubeleive]

The front end is 3 in higher than stock.
The 33s are only a tiny bit bigger but yes definitely don't help.
I've got the truck towing mirrors on it, and the "border patrol bumper cut"
Plus hundreds of pounds of crap in the back at all times.
Oh, and e85 all the time.

aah ya the e85 would do it

 

[George B]

My fuel economy on E85.

 

[89Suburban]

yeah I dunno wtf is going on here fuse is good, relay good, rear defrost button is lighting up. Still no power reaching the heated mirrors. I am wondering if the door lock control I replaced isn't programmed for it maybe?

 

[89Suburban]

Nice work as always! What's the mileage on the ol girl now?

Looks great in there

Coming up on 345K.

 

[89Suburban]

I feel like fkn Clark Grizwold with the fkn Xmas lights only it’s heated mirrors.

 

[Doubeleive]

I feel like fkn Clark Grizwold with the fkn Xmas lights only it’s heated mirrors.

check for continuity on the mirror wires

 

[swathdiver]

Purchased a power adapter to plug my dash cam into the rearview mirror. Pin 1 is ground (Black) and Pin 8 is power (Red/White). Works great, no more wires hanging off the mirror and blocking the radio.

https://www.amazon.com/gp/product/B07BFRWC3X/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1