That !@#$%^&* A/C

[tygera@rpi.edu (Allan Tygert)]

I am completely perplexed.  This damn A/C on my '86 5000cstq is making me
nuts!  Up until about a week agoair would come out of the dash vent
occasionally.  If I smacked the underside of the dash down near the A/C
programmer (but not the programmer its self) I would here the diverter valve
switch over and voila, air from the dash vents (for 5 or 10 minutes anyway).

I thought to myself, I can make this thing work.  So I pulled out the
programmer and resoldered all the joints.  Everything worked great.....for a
couple days.  Then I started hearing this chattering coming from the
programmer when the air should be coming out the dash vents.  When set to
bi-level or defrost or econ at a high temperature, no chatter.  Set to econ
at a low temperature, the solenoid chatters.  So I pulled it out again.  I
noticed if I jumpered around the solenoid that appeared to be chattering
(the one to the grey vacuum line) the chattering stopped, no air from the
dash vents, but no chattering either.  When I hit the solenoids with 6 or 12
volts, they don't chatter, just click.  

Now I'm noticing chattering coming from the radiator cooling fan 1st stage
relay (relay 11) in the panel on the drivers side under the hood.  When I
put 12 volts across terminals 85 and 86, I see continuity between terminals
30 and 87; just like the diagram says.  I'm at my wits end on this one.  

Does anyone have any ideas?  I'll mail the one who comes up with the right
answer a six pack of their choice.  

Thanks for all your continued help in keeping this car operating.

Allan Tygert
tygera@rpi.edu