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  •  » Push button switch for A/C

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    12/30/2019 4:26 PM  #1

    RV6
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    From: Pine Junction, CO
    Registered: 3/01/2016
    Posts: 1,250

    Push button switch for A/C

    Modern automobiles have a A/C on/off switch on the dash. The Custom Auto Air I am installing in my 67 does not have this feature, nor did the original 67 A/C. The compressor is controlled by where the mode and temp switches are positioned.

    So I was thinking I would install a neat little push button on/off LED switch to control the compressor operation, similar to a modern vehicle. The switch would be inline with the hi/low pressure switch, the only place I can interrupt power to the compressor. In the off position the compressor should never come on. The A/C unit draws all of its power from the original blower motor 14 amp fuse (replaced with a 20 amp for the A/C).

    Will this work, is it overkill, am I crazy for wanting this?

     

    Last edited by RV6 (12/30/2019 4:27 PM)

    Gary Zilik - Pine Junction, Colorado - 67 Coupe, 289-4V, T5
     

    12/30/2019 4:37 PM  #2

    RV6
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    From: Pine Junction, CO
    Registered: 3/01/2016
    Posts: 1,250

    Re: Push button switch for A/C

    Or should I place a switch on the throttle to turn off the A/C at WOT operation. I remember my wife's 89 Isuzu had this feature.

    The reason this has all come up is that Custom Auto Air has been less than stellar in their support. The 3 groove crank pulley they supplied has to small of a bolt circle to bolt to my balancer. I do have a original 3 groove A/C crank pulley from a 67 that  would work although the A/C drive sheave is larger in diameter than the one supplied by CAA. 

    At 5000 engine RPM the CAA supplied pulley will drive the A/C compressor at 5850 RPM. The Ford original will drive the compressor at 6950. The compressor is rated to 6K continuous and 7K MAX. 

    Gary Zilik - Pine Junction, Colorado - 67 Coupe, 289-4V, T5
       •Thread Starter
     

    12/30/2019 5:40 PM  #3

    TKOPerformance
    Hyper FYIFORD ADDICT

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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,518

    Re: Push button switch for A/C

    At WOT the compressor doesn't run on any AC system.  The high pressure cutout switch will kill it whether anything else does or not.  This is why the compressor speed, so long as its not oversped, isn't going to be an issue.  The compressor is just there to maintain system pressure.  Spun faster it may run for a shorter period of time than spun slower, but with relative speeds within reason this is kind of a potato/potato situation. 

    Those AC buttons in modern cars also don't really 100% control the compressor.  If you turn the AC off, but turn on the defrost listen as the compressor comes on. 

     

    12/30/2019 5:50 PM  #4

    Rudi
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    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,977

    Re: Push button switch for A/C

    The 68 kit came with a complete control switch assembly and I am used to it's quirky operation but I like the idea of a on/off led. I keep an eye on the voltmeter to see if the clutch is engaging.
     Although the 6K rating I would be hesitant to over speed the compressor, I would hope that CAA has determined the proper rpm for efficiency and longevity.

    Good work ain't cheap, Cheap work ain't good!   Simple Man
     

    12/30/2019 6:54 PM  #5

    MS
    Forum Originator

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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,283

    Re: Push button switch for A/C

    Place a NC switch under the accelerator pedal. Make the switch open when you mash the throttle. Then it will work like a modern Mustang and YOU WILL GET HOT WHEN YOU MASH THE LOUD PEDAL.  Why anyone would want to do this is not something I do not understand.
    Why is this even a question?
    If I turn my AC on, I want it running.  It gets freaking hot if it stops pumping...

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    12/30/2019 7:48 PM  #6

    HudginJ3
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    From: Cedar Hill, TX
    Registered: 4/29/2015
    Posts: 1,249

    Re: Push button switch for A/C

    My compressor failed because of over speeding at hiway speed. I like the idea of a switch to turn off the compressor to the AC especially when in moderate very humid days when you want some air circulation or when the evaporator freezes up. The defroster in my F150 doesn't use the compressor unless I physically turn it on, as per factory design. Let me know what switch you end up with.

    Last edited by HudginJ3 (12/30/2019 7:53 PM)

    70, ragtop 351W/416 stroker Edel Performer heads w pro flow 4, Comp roller 35-421-8. T5
     

    12/31/2019 11:16 AM  #7

    Bullet Bob
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    From: Montrose, Colorado
    Registered: 4/01/2013
    Posts: 4,888

    Re: Push button switch for A/C

    I don't know about "modern" cars but the 85 - 95 Fords EFI computer dumps the AC compressor at WOT.   I have the Vintage Air Gen 4 system which allows the compressor to be turned off by taking the temp all the way to High before adjusting back to a desired setting.  If the temp is run all the way to Cold the compressor will come back on.  Took some getting used to but I'm okay without a separate Compressor switch.  Also had a number of foreign types cars with the switch...that worked okay too.


     

    "you get what you pay for, good work isn't cheap, and there are NO free lunches...PERIOD!"
     

     

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