I pulled a fan fron a Ford Taurus SHO, fabbed some mounting brackets and bought a wiring kit from PepBoys. The kit has a 75amp relay, fuse, and a toggle switch. It did come with a radiator probe, but it broke off too early, so wouldn't penetrate all the way. Right now it's wired up like this:

Fan power----fuse----relay
Fan ground---- chassis ground

Relay power----battery +
Relay ground----chassis ground
Relay supply----fuse----fan power
Relay switch (brown)----toggle switch
Relay switch (green)----not used
Relay switch (blue)----not used (for dual fans)

Toggle switch 1----12v ignition on source ( stereo power )
Toggle switch 2----Relay switch (brown)
Toggle switch 3----Chassis ground

It definitely works... but i was wondering if anyone sees any issues I may run into??? I'm going to put up pictures later on today.

 

so do you have to flip the switch to turn on the fan?
if so, i could see that being a problem... the famous brother in law borrows the truck and doesnt turn on the fan and overheats your truck...

 

Yeah, the switch needs to be on in order for the fan to come on. But, i'm going to get a new radiator probe and put it on the other input on the relay. I'll have the ability to turn the fan on manually, or the probe will kick it on whenever it hits 185 degrees.

 

that will work. where does the probe go? i'm thinking of doing this soon...

 

The probe just pokes through the radiator fins about 3" below the inlet... I was sketch on it at first, but you just gotta be careful and not ram it home. You gotta lube it up, and ease it in, inch by inch.... like a gentleman. hahaha

 

just be carefull if you get one of the segmented ones, it tells tyou to break of the unneeded segments, and mine broke one too early.... no goin back after that, have to replace it.

 

i have mine wired on the low speed with a variable temp sensor so it turns on when the truck hits a certain temp (hard wired with a fuse inline so it continues to pull heat out of the radiator after the truck is off). I also have it connected through a relay to the high side of the fan for really hot days when towing and the low side cant keep up (i.e. towing a 10k lb trailer up 7,000 ft mountains in utah in 110 degrees). I flip a switch in the cab and it overrides the low speed, turning on the high speed. when i flip the switch off, its back to being controlled by the variable thermostat.

 

you have a diagram of that??? i really like that idea!!!!

 

do you wire both the wires from the fan motor together, or one is for high, and one is for low???

 

one is for high, one is for low... they'e totally separate from each other entirely. i dont have a diagram but i'll go out and try to draw one up for you. i'll post it on here when i get to it (hopefully tonight or tomorrow)