Best way to power fans?

[snappytravis]

Working on 69 Camaro, I have a aaw highway 22 kit that has a 40 amp relay built in, I can run only one fan off of it, I am also running holley hp ecu, I have not researched it enough to know if I can run a fan off of it throught the ac, I have seen pwm style fan controllers that looks like a pretty nice setup as well, or do I run one fan off of the relay in the fusbox and a temp switch and then run the other fan off another relay and trinary switch that kicks that fan on when ac is engaged, I am just trying to figure out what way would be the best setup and the least amount of wiring, I also have dual spall 11 inch fans.
Thanks Travis

[hifi875]

I have the same ecu. I am running a relay off of each fan output. Mine has 2

[MrQuick]

Yep, fan output from PCM to switch circuit on relay.

[snappytravis]

So can I set one up to run off temp sensor and the other one to run when ac clutch is engaged through trinary switch,or just keep it simple and when it hits desired temp they both come on. Then just don't bother using the one in my aaw fusebox.

[MrQuick]

Since the trinary switch is also a grounding circuit you can splice the trinary along with the engine fan switching. AC switch on will over ride it.

[snappytravis]

2 relays both will be temp set through holley hp, say 195 for one and 210 for the other, then run the ac through one of those relays? probably overthinking this one,
Thanks

[parsonsj]

I forget my circuit, but you can have the trinary override both fans with one more relay. Fan1 on at 195, Fan2 on at 210, both on when the trinary senses high pressure, using the ECM.

You can also get a fan controller with its own sensors and PWM control. DC Controls makes one, Dakota Digital makes one. Both allow for trinary input, plus can run fans just fast enough to keep a programmed temperature. Plus soft-start to avoid the inrush amperage spike. Reduce the load on your circuits, and longer relay life, etc.

[Ron Sutton]

I know this was SnappyTravis's thread, but my build is similar ... utilizing the AAW highway 22 kit & running two fans to kick on temperature sensitive.

Thanks for the info !!

[hifi875]

I didn't even use the trinary. I just prog the fans through the ecu. fan 1 195 fan 2 210. Even if you turn the air on it doesn't hurt anything, when the temp comes up to the trigger temp it will come on. The iac adjust the idle when I turn my air on, so I don't have to worry about the idle speed dropping. really very simple. I ran it this way on the power tour with no issues at all(3000 miles)