[V8] Out of control air-conditioner blower

[Peter A. Green]

While driving home tonight in the rain, my air-conditioner blower motor started running at high.  The 'off' button would not switch off the unit.  My first thought was to stop the engine and restart - the motor came on again at full speed.

I remember changing a ballast resistor assembly for my engine cooling fan some years ago when it had the same symptoms.  Is there a ballast resistor assembly which controls the blower motor - if so where is it located?

If you have other ideas - your help would be appreciated.
Pete
1990 V8Q Pearl