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A/C question - high/low pressure switch wiring


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Quick question about the A/C high/low pressure switch wiring. The eBay kit I purchased included a high/low pressure switch that has four wires: two blue and two black. See photo below:

IMG_0326.thumb.JPG.882a99bad3b7cf18004f04e55d72b77c.JPG

If I understand how to wire the A/C system, that switch simply goes between the thermostat and the compressor.

 

CF6AB531-018A-4ABE-90B0-3DE9CF456D01-1601-000001E77A815C6B.jpeg.ea3f09b6f4038310e50ed2c795c19796.jpegThere's one wire from the thermostat and one from the compressor. So how do I use this pressure switch with four wires?

 

Garrett

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Update for future A/C installers.  It's not a binary switch (only two wires), it's a trinary switch (duh).  In addition to the high/low pressure shutoff for the compressor clutch, it also controls the electric fan in front of the condenser.  When the A/C system reaches 255 PSI, it tells the fan to turn on, thus cooling it down and lowering the pressure.  When the system is below 255 PSI, the fan stays off, saving some wear and tear.  

 

The Mini Kooler kit I'm installing (https://www.southernrods.com/a-c-and-heat-components/all-new-mini-kooler-ac-only-small-unit.html) doesn't include a relay, so I'll have to buy one from a local auto parts store.  Just a generic 30 Amp relay kit for like ten bucks should do it.  And in case anyone's curious about how to wire this up, here you go:

 

AC_Wiring_Diagram.thumb.jpg.4c79af7b10072a19cf4d7cfa4c76fd5a.jpg

 

Probably common knowledge for most folks, but there's a first time for everything.

 

Garrett

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