Wiring for dual fans
- Thread starter Crazyx4
- Start date
ScottHeidinger
Active Member
- Joined
- May 2, 2015
How many amps do your fans draw?
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
- Joined
- May 28, 2001
B4 U do, look at the inrush, and operating amp draws....
Crazyx4
Member
- Joined
- Aug 13, 2005
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
ScottHeidinger
Active Member
- Joined
- May 2, 2015
Sent from my iPhone using Tapatalk
ScottHeidinger
Active Member
- Joined
- May 2, 2015
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.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
salvageV6
Daily Driver
- Joined
- May 25, 2001
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.
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.
salvageV6
Daily Driver
- Joined
- May 25, 2001
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
I used this:
https://www.racetronix.biz/customkititems.asp?kc=fnwk-005
Has everything there and it's very well made.
https://www.racetronix.biz/customkititems.asp?kc=fnwk-005
Has everything there and it's very well made.
salvageV6
Daily Driver
- Joined
- May 25, 2001
You can order it from Jegs and other places.
https://www.jegs.com/webapp/wcs/sto...10002&langId=-1&productId=37152&storeId=10001
https://www.jegs.com/webapp/wcs/sto...10002&langId=-1&productId=37152&storeId=10001
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Caspers has a built in delay for second fan startung this helps with lock rotor start up amps
captndave737
Well-Known Member
- Joined
- Feb 14, 2006
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
Well-Known Member
- Joined
- Feb 14, 2006
This is a good, simple solution as well.
salvageV6
Daily Driver
- Joined
- May 25, 2001
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.
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.
