PAC-2750 fan controller & Trinary switch

[2014sierraAT]

Hey fellas, I have an old air ac kit in my truck along with 2 spal electric fans. The fans are controlled by a Dakota Digital pac-2750 module. I’m trying to understand how to correctly add a trinary switch to this system. The Dakota controller has an input labeled A/C with the description “AC clutch power sense (+)”. The trinary has 2 blue and 2 black wires. Has anyone ran this setup that can explain to me which of these wires need to go where? The only installation instructions I’ve been able to locate aren’t including a standalone fan controller. I contacted Dakota Digital and couldn’t completely understand their instructions. I will post the reply from DD and hopefully someone here can understand better than I could.


“The A/C terminal is activated by 12VDC. Whichever wire you have that provides a 12VDC signal whenever your AC is enabled will work.
In most cases we go off of the signal that goes to the A/C compressor clutch. That signal is usually 12VDC.”

[HO455]

We would need to know the make and model of the trinary switch to help.

[2014sierraAT]

This is the switch I have along with it’s specifications. Also the diagram for the Dakota digital controller.

[HO455]

This link may help you get things hooked up. You may have to do some testing of the trinary switch to verify the hook up if you don't have a schematic for it.
Good luck.

https://www.pro-touring.com/threads/...-Switch-wiring

[HO455]

After some more research it appears that the normal wiring for a trinary switch is the black wires are for the compress controls and the blue wiring is for the fan controls. Using a fan controller like you have will require a departure from the drawing in the link I sent. I will try to make time tomorrow to sketch up something for you.

This link helps confirm the trinary switch wiring, but not with your fan controller.


https://www.vintageair.com/universit...rinary-switch/

[2014sierraAT]

Yeah that’s where I’m stumped too, DD says its looking for the 12VDC source that the clutch gets to trigger it. So the only way I can get it to make sense in my head is to wire it like most of the genetic diagrams show. One to common ground, one to ground side of fan relay, one to the compressor, and then just jump the last wire from the trinary to the 12VDC clutch trigger and from there to the fan controller. I really appreciate you taking the time to look into this for me also.

[HO455]

Here is the drawing. The PAC-2750 is looking for a 12v positive signal. This looks to me to be the easiest way to make that happen. With no other information for me to review about the Trinary switch I would take a multimeter and check for continuity between any of the 4 wires and the metal body of the switch. You don't want to have any continuity between them. In other words it should be zero ohms between each wire and the body of the switch and between each wire to the other 3.

[2014sierraAT]

Originally Posted by HO455

Here is the drawing. The PAC-2750 is looking for a 12v positive signal. This looks to me to be the easiest way to make that happen. With no other information for me to review about the Trinary switch I would take a multimeter and check for continuity between any of the 4 wires and the metal body of the switch. You don't want to have any continuity between them. In other words it should be zero ohms between each wire and the body of the switch and between each wire to the other 3.

Ok I’ll give this a try and report back, again thank you for your time and help!

[2014sierraAT]

I was finally able to get my system charged back up and trinary wired as the drawing you made. Everything seems to be working just like it should. Thank you for your time HO455. I surely do appreciate it.

[HO455]

That's good news! You are most welcome. Now go out and enjoy your "COOLER" truck.