Yet another No Heat topic

I've read throught all the "no heat" threads I could find, but none of them really answered the question...
I'm working on a 1997 Grand Prix that has good engine operating temp but the air coming from the blower is a hair above cold at best. I'm seeing a lot of heater core problem threads, but don't think this to be the problem. I actually suspect that the hot/cold selector in the electronic climate control unit is not sending the right info to the valve. Are the ECCs known to go out in these cars?
Any reply is much appreciated...

The Heat A/C System has two other controls you should consider. The actuator and vacuum lines. The Actuator switches the heat and cold flow. It's located up under the dash behind the heater A/C controls. Also, the entire sytem is linked to to your vacuum lines. It's possible that one of the vacumm lines is broken and the controls don't work.

Randy