My 70,000 km Right Hand Drive 1990 HC mk2 929's heater fan motor stopped working a couple of weeks ago. It stopped (I think) whilst I was adjusting the fan speed slider control from low to medium. The A/C was not on, and the heater valve was at medium. Vent control on, with air also to footwell. Now the Air cond. compressor cuts in as normal when the fan control is turned on, but there is no fan. The heater still works but without fan boost. All directional controls seem OK. It's hard for me to get under the dash (I'm in my '60's and other probs.); but the circuit breaker is in place and I think all fuses in the footwell fuse box are good. Can someone please give me a hint as to what may be the problem?

 

It may be the blower motor itself, the switch, the relay for the blower, or the blower resistor. You will need to use a voltage tester or swap parts to narrow this down.
The switch is the least likely cause since the AC is reacting to it.
In my Protege (LHD)there are relays in the driver's side footwell just above the pedals. There were two of the same kind and I switched them out. If one was bad the problem should have moved to the other circuit. They both were good. I replaced the resistor and that was a waste of money. In the end it was the blower switch in the dash.

 

Thanks TanProtege. I don't have a service manual as this was a scarce model in Australia, but I'll see if there are any panels under the dash which might hide relays or the resistor and be easily removed.

 

Hi TanProtege; gave a Mazda dealer the job of fixing the problem. 20 minutes work and the attention of the mechanics' special tool (a quick whack with a hammer) and the fan motor works again. Didn't even charge me for it (done same time as I had the timing belt replaced). Rgds, David