I reciently replaced the radiator in my 93 only to find that the blower motor, heat or a/c, runs constantly in the high mode with the car on or off. I had to pull the 30amp fuse under the hood to shut it down so not to kill the battery. With the car running and the fuse back in place the blower runs at full speed no matter what the speed control is set to. Putting the switch to auto does notihing either. The fuse terminal is hot key on or off as noted by the arc when romoving or replacing the fuse.
Relay prehaps and where is it located??
Resistor block???
Any ideas?
John

Do you have ATC? If you do u have a Module for the blower motor. It is located on the blower motor and there is a high speed blower motor relay located under the passenger side dash ATC only. If you dont have atc the resistor is located under dash. The blower running after the ignition switch is turned off I would think is because of a short somewhere! There should not be any power to the blower switch with the key off. It makes me think you might have a short possible a bad ign switch just a starting point. Start at the switch and go from there. Check wires black& orange and red& white from switch.

If atc is automatic temp control then yes I'll take a look for the module. Is there a relay to look for. I quite sure that the ing sawitch is ok because all other functions turn off with the switch only the blower motor is the problem.
Thany you for the help.
John

The only relay I know of is the high speed blower motor relay located on the right end of the heater AC Housing. The relay in the de-engergized position should have continuity between terminals 87A and 30, and no continuity between 87 and 30. If OK resistance between 75+5 ohms. If ok connect a battery to terminals 85 and 86 there should be continuity between 30 and 87 and no continuity 87A and 30.

I had the same problem with a car I had, after I flushed the radiator it happened. It was the A/C module. If you can locate it, disconnect it and see if it turns off. If it does change module.