ECU triggering of fans/increased idle speed for A/C

[Kiwi Dave]

Hi All

It's getting warm and, although it will do me zero good in my go cart, it reminds me to charge my A/C and see if everything is working.

I charged it up with the prescribed amount of R134a, the compressor kicks in as it's supposed to and I get cold air.

Next, there's the question of getting the fans to run as the Vintage Air system runs independently of the ECU. Lawson (Isfourwheeler) told me that there's a trigger wire that can be run to the ECU that starts up both fans and ups the idle speed when the a/c compressor is on. This can be teed into the compressor trigger wire from the trinary switch. Brian from iWire kindly sent me a wire to do this. With my 2007 manual a/c setup Brian confirmed that it goes into pin C24 (FYI - the FSM has this incorrectly identified in one diagram on page WI 90 as C23. It should be C24). I get +12V to it when I turn on the a/c but the fans don't run and the idle is not increased.

One thing I thought of that is also now different than the OEM a/c setup is the outside temperature sensor is not hooked up (not supported by standard iWire harness). Does the ECU need to know it is above freezing to run the a/c and therefore the fans?

Has anyone else successfully done this? What am I missing?

Otherwise, I'll wire up the fans through relays triggered by that wire.

Cheers

Dave

[Ajzride]

I’ll have to go back and check mine, it might be a 12- signal instead of a 12+ to trigger the fans. I seem to remember installing a relay to accomplish this.

[Bob_n_Cincy]

Here are the fan rules of the oem ecu:

fan rules.jpg

[Kiwi Dave]

I’ll have to go back and check mine, it might be a 12- signal instead of a 12+ to trigger the fans. I seem to remember installing a relay to accomplish this.

Thanks AJ! Please let me know. I hope it's that simple:

pos2neg.gif

Thanks Bob for the rules!

Cheers

Dave

[Ajzride]

Dave

It’s a 12+ signal. Mine is a 2006 so pins and wire colors may not match, but I suspect the functionality will be the same.

https://thefactoryfiveforum.com/show...l=1#post408894