I picked up a w/defrost HVAC controller and replacement mirror glass with heat...rigged up some wiring from the glass to the door harness...but got no power.

Anyone done this? IS there a fuse or a relay that I'm missing?

01 silverado, no defrost from factory

added HVAC controller for a silverado that had defrost and replaced glass with heated glass.

thanks

Go to dealer and get the BCM ( Body Control Module ) programmed for that option. It contols pretty well everything on the chassis.

When I replaced my mirrors with heated tow mirrors, I had to install a relay in the fuse/relay box under the hood.

I think the spot is plainly marked. The relay is about $8 at the dealer.

yep, added the relay under the hood and I'm melting ice! This is a sweet easy mod if you can find a cheap hvac controller in a junk yard...the replacement heated mirror glass is like $30-$40 from the dealer.

The wiring harness in the dash all the way to mirror connector is the same wether you have defrost or not...BCM makes no difference either (by the way - I don't think many people are going to pay hundreds if not alot more, for a new BCM just to add heated mirrors)