I'm working on a Goodman GPC34RH21AB. The AC works but when you switch over to heat it blows the 3 amp fuse on the blower control board. I've replaced the control board and the 24 volt transformer also checked for short on the thermastat wires and for correct voltage at the thermastat . The thermastat is a Ritetemp digital with the following wiring. RC - red, with jumper to RH, B - blue, W - white, Y . Yellow G - green. could the Rite temp unit be bad ? Any suggestions?