I replaced the blower fan motor on my '97 Bonneville a few years ago, and recently it started making some noise. There was a bunch of debris in there that I cleaned out. I set the motor on top of the engine, and turned the car on to see if the motor was ok after the cleaning. It ran fine, but I unplugged the harness while the engine was still running. When I put everything back together, the fan runs continuously on high speed, even when the ignition is off. I doesn't respond to any inputs from the fan speed switch on the climate control center. Anyone have any ideas on what I may have done to cause this condition? Any help will be greatly appreciated!

Is this auto temp? Auto temp uses a blower control module....manual uses a resistor block and a high speed relay......

Which do you have?

Probably the default position for the fan is high speed, once the resistor block/relay is blown.
You also may want to try disconnecting the battery cables for a few minutes, to re-set any codes that may have been stored, when you disconnected the blower motor.

Reason I asked if he had auto temp, a constant running fan is usually a bad blower module.....don't know if he arced something to the module while he disconnected it while running.....

There is no default mode for a resistor block in a manual system.....only thing I could think that would keep it running would be a sticking hi speed relay....

Yes, it'* an auto temp.

Then my guess would be the blower module.......key out of ignition, disconnect neg bat cable, remove firewall cover to relay bracket....you will have to remove the screws/nuts from both ends of bracket to get to the module(under left end of relay bracket).....