Wiring for dual fans

[Crazyx4]

Can I use the stock plug? Black wire for ground. Use one of the black/red wires for one fan and the other black/red wire for the second fan

 

[ScottHeidinger]

How many amps do your fans draw?


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[Chuck Leeper]

B4 U do, look at the inrush, and operating amp draws....

 

[Crazyx4]

6.5 amps each

 

[GNRick]

Check Casper's for a dual fan harness.

 

[Crazyx4]

I have 2 relays with the new radiator/dual fan combo. Griffin is the brand. I hooked the relays up I have an orange wire for key power and a grey wire that would go to the sending unit. I would like for the ECM to turn the fans on. I’m putting the engine back in the car. Need to know which wire or wires to use off of the stock plug

 

[hflwyo]

Get the Caspers dual fan harness it's very nice. All plug n play. Also turns one fan on at a time so it doesn't overload the circuit.

 

[ScottHeidinger]

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[ScottHeidinger]

Use the black/red wire (outside connection not the middle) if you want to control the fans only with the ECM. Make sure to use large enough gauge wiring and separate relays for each fan. In stock form ECM only controlled low speed fan. High speed was controlled by ac/temp switch on intake manifold.


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[salvageV6]

You could wire the two stock relays to control one fan each by having the ECM trigger both factory relays and eliminate the high speed switch in the intake manifold.

Run the dark green wire from ECM controlled relay over to the other stock relay and eliminate the dark green/yellow striped wire.

At the plug wire one fan to the blk/pink and blk/red wire and ground them both well.

Both will come on when the chip programmed temp. is reached.

You probably would need to know the noise level when they both come on, physical dimensions and cfm's, as well as the cooling level with what you are using for radiator, motor, shrouding, etc., before you decide how it should be finally wired.

Lo/Hi operation with a lower intake manifold sensor may also be the way to go, hypertech I believe makes 3/8" NPT temp. sensors that fit the car.

 

[Crazyx4]

Thanks for the help.

 

[salvageV6]

https://www.summitracing.com/parts/hyp-4026

 

[mr84ss]

https://www.summitracing.com/parts/hyp-4026

It says not available

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[Pronto]

I used this:
https://www.racetronix.biz/customkititems.asp?kc=fnwk-005
Has everything there and it's very well made.

 

[mr84ss]

I used this:
https://www.racetronix.biz/customkititems.asp?kc=fnwk-005
Has everything there and it's very well made.

I have the previous version and good so far

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[salvageV6]

You can order it from Jegs and other places.

https://www.jegs.com/webapp/wcs/sto...10002&langId=-1&productId=37152&storeId=10001

 

[turbo nasty]

Caspers has a built in delay for second fan startung this helps with lock rotor start up amps

 

[captndave737]

If you have 2 relays for the new fans you can take power from the battery to the fans (hot Wire) and have the stock connector?ECM control the relays. The coils draw very little power and it will make no difference if both come on at the same time. Pretty much what the various plug and play harness do anyway.

 

[captndave737]

https://www.summitracing.com/parts/hyp-4026

This is a good, simple solution as well.

 

[salvageV6]

Crazy, you can't control the added relays with the stock wiring the way you have described it, I just read your second post.

The stock fan plug provides +12 to run the fans from the stock relays and your added relays are expecting a ground signal from a sending unit. The body of the sending unit is grounded and the one wire out of it gets grounded when the operating temp. is reached.

You could add the hypertech switch at a lower than stock temp. and wire that to your gray wires and both fans will come on around 170 degrees, I would also install a manual grounding switch if you decide to do this in case that sender fails or you wish to turn the fans on manually.

If you use the stock relays to control the fans or to control the secondary relays when rewired from what you have described, then I would get a Caspers HI/LO fan switch which would provdide manual control of the stock relays and thus the fans.