Trinary Switch without the high/low exist?

[Vetteman61]

Hello,

I'm curious if a switch like this trinary switch exists without the high/low cut off for the compressor, so it would only essentially control the fans at approx. 250 psi? For my custom setup, I have no need for the extra wires for the high low and would prefer to find a switch without them.

[andrew vanis]

why not just use the high side switch to trigger your fan and not connect any of the other wires to anything else?

[Vetteman61]

The high side switch on these activates over 300psi, which is far too high for a fan to turn on. There are 3 wires, high/low/fan. I do not need the high low, and am asking if there is a part that only serves what the 3rd wire would do, which is turn the fans on at 250psi.

[bohica2xo]

GM tech covered this in your previous thread:

https://autoacforum.com/viewtopic.php?t=14870

There is a 250 psi switch available for the high side port in the back of the A6 head

[GM Tech]

Be careful-- lots of outlets call a 3-wire transducer a "trinary switch" Seen it many times. A transducer tells the ECM the exact pressure and the ECM decides when and how to control fan(s) etc. In a three-wire transducer, one wire is ground another is 5volt reference and the third is the return voltage that varies with pressure. So it is always best to see the circuit it is used in to decide if it is truly a "switch"

[Vetteman61]

Thanks Tech. I almost made that mistake earlier when I looked to see if the transducer I used for another project that came from a 2000 S10 4cyl would work here and discovered what you explained here.

[tbirdtbird]

Just re-read your other thread.
The experts here are some of the best minds in the MVAC business. They may occasionally suggest a different way to a poster based on their experience