I know there use to be a thread on here that had a diagram on how to hardwire your cooling fan....anyone able to point me in the right direction or hook me up?
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Are you referring to the cooling fan mod, or are you wanting to truly hardwire the fan to a switch? Where it will only come on per that switch and nothing else?
FU Tuning
Well basically what happened is my cooling fan was not coming on at the right times to keep the engine properly cooled. so a friend of mine bought a relay and hooked it up and ran power to the relay, grounded the relay, and ran one to the fuse box i believe??? it's worked fine for over a year and now the fan doesn't come on at all. so i was looking for the diagram so i could trace the wires to make sure it's still hooked up right or if i have to replace the relay i want to be able to hook it back up right...basically anytime the igntion is on the fan would come on...hopefully this makes sense lol
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ok..i dont know why he bought you an extra relay..sounds like you need to throw all that out...if you look in your engine bay there is a black fuse box on the driver side..one of the big relays will be labeled "cooling fan" ...pull that box up and look under it...if you look under the relay on the bottom of the box there should be 4 wires ...3 thick ones and 1 small one..the really small one is a green or light blue color iirc .. just splice into /dont cut/ that wire ..run it to the cabin, hook it to a switch,then run the switch to ground..its that easy...now, when ever the switch is ON the fan will come on..whenever the switch is OFF the fan will work just like its supposed to..cus all your doing is grounding the relay to the fan and making it come on when you hit the switch
scott (section8cav) wrote:ok..i dont know why he bought you an extra relay..sounds like you need to throw all that out...if you look in your engine bay there is a black fuse box on the driver side..one of the big relays will be labeled "cooling fan" ...pull that box up and look under it...if you look under the relay on the bottom of the box there should be 4 wires ...3 thick ones and 1 small one..the really small one is a green or light blue color iirc .. just splice into /dont cut/ that wire ..run it to the cabin, hook it to a switch,then run the switch to ground..its that easy...now, when ever the switch is ON the fan will come on..whenever the switch is OFF the fan will work just like its supposed to..cus all your doing is grounding the relay to the fan and making it come on when you hit the switch
The fan was coming on when the car was in park and never came on when i was driving so I don't know if thats why he used the relay or not??? I'm not the best on stuff like this so who knows lol. color me stupid...but like i said i'm not the best with this stuff...when you say cabin do you mean the fuse box? and how do i splice into a wire without cutting it?
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The fan was coming on when the car was in park and never came on when i was driving
thats actually how the fan is SUPPOSED to work...the fan simulates the car moving creating an air flow thru the radiator..when the car is moving the fan doesnt need to come on...
and when i say "cabin" i mean the place where you sit and drive..thats a cabin..and theres a couple differnt ways to splice into a wire..you can "shave" some of the insulator off the copper and just wrap a nother wire around that and put some tape over it( which will work but isnt the correct way) ..or the RIGHT way.. they make a splice connector(cheap) sell them at any autoparts store..where you just put two wires in it and crimp it together..that will splice wires together without "cutting" them in half
I just wired a hot 12-volt wire from my fuse block to the switch inside my car, then from the switch out to the fan. Easy enough, eh?
I just spliced into the small wire on the relay, and stuck the other end of it into my igniton fuse in the dash, lol.
So you guys are saying the diode and resistor in the said website is pointless? With my basic knowledge of electronics Id say just a wire and switch would do. If you wanted to you could wire in an inline fuse, but if all the thing is doing is just interrupting a signal from the PCM, the inline fuse would protect it against any kind of short.
Just tap into the blue wire going into your fan with a 12 volt supply.
Just have a wire from the battery to a switch in the cabin and from that switch, run to the fan's blue wire.
The fan will work in every way the manufacturer intended as the external power is not affecting the relay at all.
It'll still come on with the a/c and gives you a true override from the stock fan relay when you want it.
It couldn't be easier and have done this to every car I've ever owned.
It's too simple and everyone seems to make it so difficult in hooking it up.
No relays, diodes, or fuse boxes are needed.
Just make sure that the switch you're using is rated for at least 15 amps @ 125vac. Most switches have specification that will have this information.
Good luck with this.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO! 
anyone thats hooking up crap to their ignition or the battery is wasting time..and power......ive said this before..and the diagram above even shows it,,, you splice into the GROUND wire under the fan relay..its very simple, and run it to your switch then to GROUND..thats all there is too it
The diode is just for safety. It will work without it, but think of it as a bit of insurance since you don't really know what goes on in the ECU.
The resistor is only there to allow the LED in the switch to work. If you don't have a lighted switch, you can ignore that.
