2002, Honda Civic SI: heater fan stops working episodically with no pattern. It's not a fuse, or the blower motor or the switch control panel, the latter having been replaced and the motor tested (they were going to put in a newe one but testing found it worked). I've taken out the relay and put it back in, but not replaced it. The fan works, then stops, then works again. Any diagnostic ideas that I can pass on to the techs at Honda who appear to be stumped? All speeds work or none work.
The blower transistor is a very common failing component. For the price that they sell for, I would actually just replace it (it's bound to fail sooner or later) and see if that solves it.
February, 28, 2011 AT 11:27 PM
Well it should be a simple matter of tracing the lack of power back from the motor to where it starts when it falis to run. Also it could still be the motor with a dead spot in the commutator or sticky/worn brushes.