Intermittent Heater Fan

[Chet]

Ph2 172 with climate control.

When i got my 172 the fan didn't work at all, i replaced the mosfet in the resistor pack and it worked for a couple of months. Now its getting very intermittent, it might not turn on for a minute or two when you get in the car or will come on for a minute and stop for 10-15 seconds and then back on. It doesn't seem related to anything else being on or going over bumps etc. It can go on/off sat in traffic.

I'd assume if the mosfet went it would stop completely.

Any suggestions? Fan itself maybe?

 

[Ianboom]

If you remove the plug on the back of the resistor pack and bridge the 2 outer pins on the plug itself, with the ignition on, the fan should run on full. If it doesn't or it's intermittant, could be the fan is faulty. You could leave the pins bridged out for a couple of days to prove the fault is the fan motor.

Ian.

 

[Chet]

Thanks, i've just done that so i'll see how it behaves on the commute tomorrow