Anybody know if my 03 F150 has a trinary switch on the a/c, if so, where is it ?

 

Ford did not use trinary switches.

 

What is a Trinary switch?
Just asking, thats a new one for me.

 

yah curious here too

 

It's basically a safety switch for your A/C, that senses overpressure in the system. Modern big rigs and cars with electric fans use them to activate the fans at slow speed to keep the pressures in check. They are the best thing to use on e-fans, because the fan only runs when needed, instead of all the time the A/C is on. Spal controllers show a hook up for them in the installation instructions. I'm going to find out if one can be installed in my A/C system. To be continued.........


Bob

 

That's a pretty good idea. I don't think you would really need the efan when you're running in the defrost mode.

 

anytime the compressor is on you want the fans on, including defrost

every car i know of uses a high and low pressure switch on the AC system. Its simply compressor insurance/safety.

 

Did Google quit working???

 

Google still works! I simply asked a question among friends

 

Well, I ordered a Spal dual fan controller kit for my Troyer fans, but have yet to solve the trinary switch mystery. I've been told that it can be added, but it takes the place of the present high pressure switch. Does anyone know if this will work and if so, which switch should I use. I'm not sure of the high pressure values in an F150. Also, where is the high pressure switch located. I think it's on the drier. Not 100% sure, though. Thanks

 

I spoke with a few Ford a/c techs and most agree that a Taurus, Crown Vic, Lincoln Mark, etc. trinary switch would probably work, but none were sure if the cut out pressures were the same as the F150. Anybody know? They also claim that they can be swapped without evacuating the system. Also, I located the high pressure switch. I'm determined to make this work.