Coyote Air Conditioning wiring

[bartock]

I know this has been asked and answered 100 times and I think I get it...but want to do a sanity check. I have a Gen 1 Coyote, ron francis harness and letting the coyote pcm run the fan. Right now I just have the wire from the coyote harness going directly to the blue wire on the fan and spliced into the wire from the Ron Francis harness. It kicks on when it should...all is normal. I figured this way when I got to this point, the AC or the coyote module could trigger the fan.

I am installing the AC from Northracecar. Looking at the Gen3 Coupe AC diagram It looks like I should be able to take the green Fan Thermo Switch wire and run that to the trinary switch. However earlier in the instructions it calls for splicing a wire into the Ron Francis relay. I have already closed up the footbox and would need to pull the fuse panel out to get to it.

My question is why would I cut into the wire by the relay when there is a lead for the thermo switch that should trigger the relay already? Unless I am just completely getting the diagram wrong.
Thanks in advance!

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[edwardb]

I'm pretty confident this response fits your situation. I've done A/C with a Coyote in my Coupe and with an LS3 in my hot rod truck build. What I found is that there are two pathways for the cooling fan to run. One from the crate motor PCM that is controlling the fan based on engine temp. So wire that one per the crate motor instructions. And the second from the trinary switch that runs the fan based on A/C pressure, shown in the schematic you posted. The first time I ran across this with my Coupe build I questioned it, but was assured it was correct. It just completed it's fourth driving season and works perfectly. The truck also worked correctly.

[bartock]

I'm pretty confident this response fits your situation. I've done A/C with a Coyote in my Coupe and with an LS3 in my hot rod truck build. What I found is that there are two pathways for the cooling fan to run. One from the crate motor PCM that is controlling the fan based on engine temp. So wire that one per the crate motor instructions. And the second from the trinary switch that runs the fan based on A/C pressure, shown in the schematic you posted. The first time I ran across this with my Coupe build I questioned it, but was assured it was correct. It just completed it's fourth driving season and works perfectly. The truck also worked correctly.

Thanks thats what I was thinking...the instructions showing to splice the wire by the RF relay was throwing me off a bit. I am not using a separate fan thermostat switch and letting the coyote pack run the fan already so it looks like just using that wire to the trinary should work then. Splicing by the relay would make more sense if I was using a thermo switch. I have the coyote fan wire and the RF fan wire spliced together by the fan connector already so the trinary should trigger the RF relay.

Appreciate it!