99 civic EX. I made a mistake and shorted out the wires running to the heater motor. Thought it should be a fuse issue but the fuse is fine and the fan was on high and would not turn down or shut off. Running full as soon as the key was turned on. I pick up a transistor at the salvage yard and installed. Now I have high when the dial on the dash is on high but once turned down to the next setting the motor stops and stays stopped until turned to high. Any Ideas of what I should look at next?

Thanks in advance for any input
99tealex

 

It's more than likely the resistor for the blower.

 

Thanks, Does the 99 ex have a resistor and a transistor for the fan motor?

 

OK After looking in to the heater motor problem a little deeper. The part I replaced was not the Power Transistor but the High speed relay switch. It is very visible under the passenger side dash 4 pin connector. To get at the Transistor you need to take out the glove box. It has a three pin connector and sits down in the blower housing. You need to drop out the fan unit to remove and replace the power transistor. With a replacement transistor in place my heater is working properly.