Climate control problems are no fun

Do you understand how the system works.
There are two systems electrical and vacuum

It sounds like you have an electrical problem most likely with the control unit. I replaced mine this summer as I fried it in trying to investigate my vacuum leak (disconnect the battery).

THe vacuum system can be checked using a vacuum checking device (hand held pump) that you can buy at any parts store.

Ok Back to theory. The climate control unit controls the opening of switchover valves which the supply vacuum to five vacuum circuits in your cars interior. (Vacuum elements open up the vents) The climate control also controls the fan blower and the monovalve which controls the temp. The blower fuse on your car should be blue and 25 amps carefully check that fuse and to be on the safe side replace it. I do not think that there is any other protection for the climate control unit.

There are many links in the forum to diagnosis the vacuum lines and problems. Check the green source line under the hood as it enters the fire wall.

THose control units are expensive about 200 bucks rebuilt.

good luck

bob