AC/blower motor will not shut off!

[trintrick]

95 s500 sedan.I put the ac on this morning and now the ac/blower motor does not shut off when I press the off button or with the key out of the ignition!. It's stuck on high. Played with the other ac control buttons and it performs what its supposed to do but the auto,low and high switch does not slow or speed up the blower. The ac and windshield defogger works fine. I had to disconnet the blower regulator to stop it. Is there a relay between the switch and blower that might have stuck. Please advise on what may be the problem?