Ok, here's the deal...

The air flow controls on my Mom's 850 do not work. I had a reputable mechanic look at the problem...he took a brand new a/c control unit, stuck it in there and nothing. Replaced two of the vent control motors...nothing. Check continuity with the wiring harness and still nothing. Is there anything else that could be causing this problem? To me, I think it's the harness. I mean, if You replace the controller and the motors and the only thing else it could be would be the harness, right? Anybody got any ideas? The mechanic is stumped...he cant get any help from Volvo and several other service companies that he knows, have never heard of this problem. This all started from having the evaporator replaced. When he put it all back together he ran into this problem. He thought that he messed up the controller somehow and replaced it at no cost. Thing is, that didn't fix it. Then he got 2 new vent motors. Needless to say, that didn't cure it either. I figured I would get on here and maybe get a new opinion on this matter...Thanks!

ASZ