I have been working on the heater box/core ect.....When I hooked everything back up the blower only blows on high speed (3)....does nothing on low(1) and medium(2).....it was spinning at different speeds 1,2 and 3 before I "fixed" the heat problems...what could have caused this ?
Thanks Scott

 

Chances are very good that the heater resistor has opened(bad). When the motor runs on high it's a direct connection allowing full 12v to the motor, low and medium pass through a resistor to limit the voltage and therefore the current. It's mounted on the box.

 

Thanks so much Scott