Adding high pressure switch to older unit help.

[tbirdtbird]

GM- "There needs to be a separate relay or diode in the circuit to avoid this." This is how I have always done this (relay), especially since these spal fans are easily drawing 12 amps

[Vetteman61]

I stop receiving notifications on this thread and didn't realize there had been responses.

GM Tech, I agree, I also do not want the fans spinning when not needed, which is why I have determined the pressure sensor to be my best alternative. Would the sensor that went in the back of the old A6 compressors mount in the same port that I could purchase and have spliced into the high side of the AC line?

[Vetteman61]

GMTech, I looked up the switch you mentioned. It was exactly what I had in mind, but it unfortunately didn't turn on at the PSI I needed. Thank you, however, as you're the first person to actually answer the question and provide the information rather than just tell me to do it a different way.

Even though the switch didn't fit in the correct PSI range, I was able to use some of the terminology on the specifications to help locate others. Do you believe this would be suitable for an automotive AC system?

(Link deleted)

[JohnHere]

... . Opinions vary, but setting the high (fans on) limit to around 250 PSI and the low (fans off) limit to around 190 PSI seems reasonable. ... .

Does the pictured pressure switch operate at or around the previously mentioned limits? If so, it can likely serve your intended purpose.