Trinary Pressure Switch Alternative..???

[wwest]

This has not yet been tried/tested.

There is a simple DIY mod that could possibly be used to avoid the front blower, or any aftermarket condenser cooling blower, from running continuously whenever the clutch is engaged, say when the engine fan is adequate.

Assuming you don't wish to use/install the Red Dot 71R7500 trinary pressure switch which would undoubtedly require a full system evacuation and recharge.

Tape and insulate the referenced Senasys thermostatic switch, P/N 2570F099-187, $9.75, to the high side hose nearest the compressor an is possible. Use the switch to supply power to a new relay.

Switch closes to activate blower at 130F (~200 PSI), opens at 115F (~160 PSI).

Blower then does not run unless needed, plus helps to keep the high side pressure at a more optimal level for condenser heat transfer efficiency.

http://www.senasys.com/shop/products-page/thermostatssnapdisc3-4/2570-34-sealed/75-inch-diamter-pipe-mount/2570f099/

[DaveMcKenz]

That looks like a great idea, and basically makes a standard binary switch into a trinary. They also have a range of control temperatures available. In my case, my car comes up to 225PSI pretty quickly and just stays there, even with all fans working. Therefore I don't think mine would cycle except at initial start-up and shutdown. I could be slightly overcharged, I guess.
Thanks
Dave

[Discseven]

Very nice Will. Am going to get my system back together then deal with.

Just went website --- temps the switch operate at can be chosen by buyer.