Heater Problem

I have a 2005 Chevy Malibu that I tow behind my RV. Last year while replacing fuse #20(under the hood)I neglected to turn off the key.(key is to be in run position and fuse pulled while being towed). The heater quit working. Checked all the fuses disconnected the battery over nite... nothing helped. It came back after 2 months all by itself. Well I did it again and can't seem to get the heater working this time. Any ideas?
Thanks Jim

I had the same problem. Intermittent working of the heater. Took it to the dealer who repaired it under warranty. The control doors use fancy motors called, "pulse count motors". The motor for the heater door was defective.

More information, http://delphi.com/manufacturers/auto/micro/cmos/qpcd/