A/C troubles.
 

On my 2005 GTS, my tech is having trouble locating the problem (doesn't charge me if he can't fix it). He says it is something electrical, as the coolant is charged and the compressor is fine. He's checked relays but still can't figure it. As soon as he pressed in relays, it worked.

Well again it stopped working recently (well it blows out some mildly cool air). However the three times this has happened, it was after I had used the heater. Does such a behavior ring any bells to why it will work, UNTIL I use the heater? Thanx.

bad expansion valve

Mechanics are not HVAC smart.