A/C cutoff switch - Team Camaro Tech
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post #1 of 7 (permalink) Old Dec 14th, 08, 07:24 PM Thread Starter
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A/C cutoff switch

Not sure where to post this, so I'll try here. I'm looking for some type of switch to cut my A/C off during full throttle application. I was at the PRI show in Orlando Saturday, and someone suggested either a proximity switch on my carb linkage or a vacuum operated style coming off the intake manifold. I've got a Holley 750, Vintage Air and AAW Classic update harness. Thanks, Kevin
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post #2 of 7 (permalink) Old Dec 14th, 08, 10:00 PM
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Re: A/C cutoff switch

You could use a micro switch and wire it somewhat like a nitrous system.

Are you wanting to turn off the whole system (blower fan, AC electronic controls, and the compressor) or just the compressor ?.

If you add in a relay a signal from the micro switch would open either the whole AC circuit or just the compressor clutch circuit.

Basically terminal 30 on a relay would go to the power feed for the whole AC unit or to the output from the AC's electronics for the compressor. Terminal 87A would go to either power the AC unit or go to the compressor. With 30 and 87A being the normally closed contacts power will flow through the relay.
If you then jumper from terminal 30 to 85 on the relay and then run terminal 86 of the relay to a micro switch that when closed (and connects terminal 86 to ground) it will open the contact points 30 and 87A thus stopping current flow to either the AC unit or the compressor.

I would think a 30A relay would work for just the compressor but if the AC unit has a 40A fuse or larger for it you need to run a higher amperage relay so it will work properly.

If I had a preference, I would interupt power to the AC clutch as some electronic controls might not like being turned on and off rapidly.


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post #3 of 7 (permalink) Old Dec 15th, 08, 05:15 AM Thread Starter
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Re: A/C cutoff switch

I was just wanting to cut the compresor off, not the entire system. Kevin
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post #4 of 7 (permalink) Old Dec 15th, 08, 06:51 AM
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Re: A/C cutoff switch

You could use the switch on the throttle arm that is normally used for the cowl induction system.


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post #5 of 7 (permalink) Old Dec 15th, 08, 09:46 PM
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Re: A/C cutoff switch

How about a turbo 400 kick down switch, also the carbed 1980's caprices had the ac cut off switch on the gas pedal under the dash.

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post #6 of 7 (permalink) Old Dec 16th, 08, 05:15 AM Thread Starter
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Re: A/C cutoff switch

I found these at Summit. They may work.

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post #7 of 7 (permalink) Old Dec 16th, 08, 01:15 PM
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Re: A/C cutoff switch

didn't some gm's come with a vacuum switch factory to do the same thing? wide open throttle, low vacuum, opens the electrical connection. would be easier to package. don't remember what years, models though.
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