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My 72 coupe A/C controls are not working properly. I cannot get the switch in the console to disconnect so that power is not going to the A/C compressor when the console rotary switch is "rolled" up to the off position. The problem is that the "point" switch is not properly opening the contacts when the rotary switch is set to off. I have tried adjusting this switch with no results. Is this "point" switch available separately from anyone. Everything else in my control unit works just fine. Any ideas would be appreciated.
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Re: 1972 A/C controls
Don't have a '72 AIM, but the problem may not lie in console control switches. My '71 was a special year where a set of 'smart relays' were used to turn the AC compressor clutch ON (regardless of AC control settings) during engine shut down to place additional drag on the engine. The system and it's theory of operation is nicely described in the Chassis Service Manual (all the little nuiassences between Corvette, Camaro, Chevy, Chevelle in that given year) plus AC vacuum and electrical diagrams which are repeated in the C60 option section of the AIM.
In some of the theo-op discussions of the CSM, they tell/warn service tech's that certain systems are designed to run the blower fan (even if the fan switch is OFF) anytime the AC control switch is turned to AC/cool. Other warnings indicate the fan can be expected to run in 'burst' mode when power is removed from various circuit points during troubleshooting probes.
This implies that the control switches 'talk to' a smart relay who has the ability to over-ride switch settings. So, if thus and such is true, you might be fighting a problem where there's a control relay that's bad or 'thinks' it sees a given control switch settng that isn't really true.
I don't have a copy of '72 CSM/AIM to read/interpret for you, but I think you catch my drift--could be an upstream control relay issue rather than a discrete switch problem. -
1972 A/C controls
Thanks for the info Jack. I know what you are talking about with using
the A/C to drag the engine down to a stop. That is not the problem here.
The "point" switch in my control unit is not working properly. I can
here is switch on and off when I move the control wheel. The problem is
that some times it doesn't switch off (points open up) when the wheel is
moved to off. You can definitely here the "click" when it does work
properly.Comment
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