1992 Acura Vigor Heater/AC Fan Problem

I have a 1992 Acura Vigor heater/AC fan problem. I don't think it is the fan motor itself. Everyday it will work on the first starting of the car (most of the time). It will start blowing air in the car sometimes when
I'm driving on the freeway (the fan comes on). Once the fan is on it stays on until I turn it off, then nothing on the next attempt. Once it came on when I hit a bump, thus I think it is in the switch or electrical connection. Any advise?
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We had a similar situation on the alt.autos.volvo group this past month. The symptoms pointed to the control circuit and led us a merry chase, but it was really dead spots in the commutator of the blower motor. If you can get your finger or even a popsicle stick on the fan squirrel cage when it isn't working, giving it a little nudge will tell the story. If the motor has dead spots it will start and run until you turn it off. Then it might or might not restart, depending on where it lands. If you can turn the fan motor an "o'clock" or so without it taking off, you can pretty much rule out the motor. Alternatively, if you can measure the voltage to the motor when it isn't working that will tell the story.
Mike
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