01 Deville window woes
 

Hi guys,
First off, I'd like to express my gratitude that there's a seemingly knowledgeable Cadillac owners site on the net. Most of the other ones I have been to are just full of people saying "take it to the dealer."

Anyway, on to the problem:
The front driver's side window and rear passenger side windows don't work. No up or down - the motors are fine, as per my power probe test (the front driver's window regulator is off track, but the motor is fine, i'll worry about the track once I've got the window working.) Using a GM Tech 2 (which I have, but have had no formal training on and I'm still learning how to use) I have no communication to either the DDM or the driver's window switch. Using this, coupled with the fact that the old door module was grounding the power feed (the large orange wire in the four-wire connector all the way to the left) I diagnosed a bad DDM. Purchased a new one, installed, and no change. Still no communication. I suppose it's possible that it's bad too (new doesn't ever mean good) but I'd like to rule that out for now.. it was supposedly tested before being shipped to me, and I have had nothing but good, well tested parts from this supplier. I've never had a bad one, and I'll take him at his word. Using the Tech 2 it claims no communication - to verify the Tech 2 works I can communicate with and operate the windows on the front passenger side and rear driver's side no problem. They also work at the switch for those doors. I have verified power going into the module, as well as a good ground at the same connector as the power. The other two wires on that same connector lead to the motor - and jumping them with my power probe leads to the motor working. So at this point, i'm wondering if the switch being bad would stop communication to the DDM, or is it the other way around? Pulling codes I get a Class 2 data link error, as well as several unrelated codes.

Halp?
Thanks in advance,

Jonathan.