Heater Fan Control Works For Only a Moment
 

I have a 1990 C2 Targa and the heater fan stays on for just a moment and the defrost mode does the same, makes it tough on cold mornings without a defroster and fan. Any suggestions are appreciated, Thanks in advance.

I have a 90 C4 which had a similar problem. In my case the rear blower had run it's bearings and seized. This had the effect of causing the heater not to operate as the fwd fans would not run if the temp was set above ambient. During the summer I had not noticed this, as the AC functioned, but at the first blast of the Iowa winter it was very evident.

I just bought a '91 C4 Targa and my front fan only runs for a moment when I turn the key on, then it shuts off. It will stay running if the temp setting is at its coldest setting. I cleaned lots of dust off of the thermocouple in the panel but no change. What was the solution for yours?
I dont know if the rear fan is running. When should it run?

The rear fan should run if the temp gauge in the cockpit it set above ambient air temp. Set the temp to max and turn the key to get the electrics on, you do not need to start the engine, the fan will be easy to hear in this configuration.

Bob Ellis
90 C4

Robert, are you saying that the fwd fans should only operate when the temp control is set at full cold? Or do you mean that if the rear fan is not working then neither will the fwd fans?

If you are trying to get heat, then the front fans will not work unless the rear is running. Dont't ask me why!!

Bob Ellis
90 C4

BTW, the fuse for the rear blower is in the engine compartment. This fuse was changed during MY 90 from a 25 Amp rating to a 30 Amp fuse. The fuse will often fail as the motor begins to seize. If you find the fuse blown and after replacing with a new one the motor is noisy you will need a new core for the fan.


Bob Ellis
90 C4

I found the blown 30amp fuse, replaced it and everything is working. I'll check the motor out this weekend to see what its drawing.
Thanks for the help!

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Louis
'91 C4