It stays on no matter what. Taking previous advice from this site, I've changed the a/c switch, a/c thermistor but no luck. I get cold air all the time.

Also second question: my oil pan is leaking like a sieve. I am fairly confident and have done lots of my own maint. How hard for a do-it-yourselfer?

It's an 88 626 non-turbo five speed.

The AC is switched on and off by a thermostat wich operates an electric clutch in the drive pulley on the compressor. Try disconnecting the wires from the clutch and see if that stops it. If not you have a mechanical problem with the clutch. If it does stop it, you could make a bodge repair by getting a thermostat out of a domestic window mount airconditioner or suchlike, and wire it into the feed wire to the AC clutch. If you put the new thermostat in the cabin somewhere, you will have "climate control".

If you haven't checked the thermostat itself, you can find it by looking under the dash in most cars and tracing the metal tube that runs across the front of the A/C outlet.

Thanks. I'll try that.