Re: HVAC '84 733i Is this particular problem typic (archive)

The contacts in the microswitch are dirty. The microswitch is on the thumb-wheel board and if you check for resistance between contacts 1 and 3 I bet you will have resistance. Remove the top cover of the switch, sand with 320 grit paper carefully between the contacts and check with ohm meter again. Replace switch cover and secure with 2 mini screws available at radio shack.

Randy

I have half heartedly searched the archives.

Defrost button push works. Light comes on, Fan runs.

No heat or A/C buttons light. No low or high speed fan.

Fan thumb wheel causes relays to click, and some vaccum switches to move.

On-off-on-off 3 times of the fan thumb wheel and vacuum relays move and the vacuum pump comes on for 15 seconds then turns off.

The problem was a slow deterioration. I could click the fan thumb wheel repeatedly and get the lights and everything to work. finally nothing.

So, I pulled the controls, looked at the chilton wiring diagram, compared what I saw and got scared.

The thumb wheel "works" since it activates vacuum switches. The blower works cause it runs under defrost.
I assume the push buttons work, cause until total failure they would switch heat modes and it took the thumb wheel jiggling to get things to go.

I've tried to look at the various discussions but nothing jumps out at me. Is there a specific archive I can review?

Any help will be appreciated.

Kent

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Re: HVAC '84 733i Is this particular problem typic Kent 15:15 4/23/2001 (0)

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