....mirror on the driver side quit working. It wont fold or move. The passenger side will move and not fold all the way. Mechanic said the mirrors need reprogrammed? I just assumed this was a plug and play part. I replaced because a window wouldn't shut but the mirrors worked fine. So, I plugged in the original to see if replacement switch was bad and drivers side mirror still doesnt work and yet it did minutes before with this switch. Looking for ideas. Thanks.

 

You're probably looking at an issue with the mirror motors and not your master switch. Or sometimes they get "stuck" where you can manually fold them in, then try the switch to open and they'll start working again. We're having the same issue with our Escalade and I haven't been able to fix it, probably have to replace the whole mirror, wasn't worth it to me just to have them power fold. There is a video on YouTube of a guy completely disassembling the H2 mirrors and repairing the motor if you're really that determined. I've always wanted to put the extending full size truck mirrors on my H2 but don't know how I'd be able to get the wiring converted

EDIT: I think I misread your original post. The mirrors were working before you replaced the switch? Its possible they got out of sync, try the manually moving method. I've disconnected my master switch plenty of times with the battery connected and I don't think I had any issues. Maybe try resetting your battery ?

 

Is the replacement DDM (drivers door module / window switch unit) one specifically for the H2? I ask because while they are identical to the ones in the GM trucks they actually have programming in them specific to the H2. One from a truck will fit and plug in fine but things like the global windows up/down buttons will not work and my guess is the power folding mirrors also might not work.

The manual says to reset them, fold and unfold them at least three times which resets their detent position.

According to the service manual, the Tech2 can only actuate the mirrors folding function. There is no calibration or anything. Not sure but possibly the DDM can be programmed with H2 software if it did come from a truck or SUV. I do know that I could not get a 2003 one to accept the programming for a 2006 even though the DDM's are physically identical. I wanted to because I wanted to add the globals windows up/down (buttons on the heated seats switch) to mine. I added that switch but the global buttons did not work. So I connected a Tech2 and it actually registered me pushing the global buttons but nothing. Tried to get it to program the software into the DDM for a 2005 and it refused. I had to get a DDM for a 2005. Once I put the 2005 window switch module in the global windows buttons worked.

It is potentially an issue with the mirror motors themselves though. Another member on here did a writeup on removing and servicing them.