After seeing cruzinhighs dual fan setup (nice!) I thought I would post what I did...
Here is how I did an electric fan installation on my 1984 GMC ½ ton:
The fan came from a ‘98 mustang V6 (used $30).
I used a fan controller from Autozone, part 733652, $25. It included a fixed (set temperature) thermostat switch, wiring harness with relay, and fuse. You can also buy a different controller with an adjustable thermostat switch that will let you dial in the temp. that the fan comes on, if you prefer. Some fans may require a heavier duty relay than this 30amp setup, be sure you use the correct relay if you use a more powerful fan…if you try to ‘make it work for now’ with the wrong relay you’ll burn it up and be out of commission!
I spent around $10 additional in wire, connectors, etc. Grand total: $65
This is an easy project. I have pretty limited mechanical/electrical skills, and I had zero problems. The hardest part by far is figuring out how to setup the wiring, and if you buy the above controller kit you bypass that step! You could even buy the above controller and replace the 30 amp relay with a larger one if you don’t want to do the wiring and need a bigger relay.
1.) Remove stock fan shroud, remove 4 nuts from in front of stock fan. Remove fan and replace nuts. (You
may need to bump the fan with a mallet to free it).
2.) I ran power to the thermostat switch from the wiper motor. This way the fan can run whenever the
key is 'on', and will not remain running after your leave your car. Install the thermostat switch
between fins near the upper right hand corner of the radiator (as you face the grill), close to where
the coolant hose comes in.
3.) If you have A/C, there is a wire to hook up to the A/C clutch so that the fan will run whenever you
have the A/C on. There is also a wire provided so that you can turn the fan on/off with a toggle
switch if desired.
4.) I ran the fan to the truck battery, and a fuse, using the fan controller wiring.
5.) Mount the new fan to the radiator, I used machine screws through existing holes in the fan shroud and
drilled into the top and bottom of the radiator, you can also buy mounts that pull through the radiator
fins if you don’t want to drill.
I had to cut some plastic off behind the electric fan motor to clear the water pump
pulley. (If you bought a used fan and haven’t checked to be sure it runs, do so
before mounting it)
6.) Run a ground from the relay, and one from the fan, to bare metal. Run the correct
wire to the fan motor form the wire harness.
7.) I recommend using male and female connectors or wire nuts instead of soldering for
connections. That way you can remove components without cutting wires if need
be later.
8.) Fire up the engine and let run, watching your temp gauge to be sure that the fan
kicks in before things get too hot. If the fan doesn’t kick on it’s time to get out the
voltmeter and play detective.
http://www.fordmuscle.com/archives/2003/02/electricfan/ - this is the link that made me pull the trigger on this project. They did the swap on a 5.0 L mustang that they race.
If you google “junkyard electric fan swap” or “e-fan installation” you’ll get more advice & good reading material than you can shake a stick at. Most failures seem to be from starting out with too small of a relay with high powered motors. There are many excellent new kits available from folks like Permacool, they’re just too rich for my blood $$$…
I felt a definite difference in engine response without a doubt. My truck has the 250 straight 6, and I got my best mileage ever after doing this project, 21.4 mpg. Before doing the e-fan my mileage ranged from 14-19 mpg, and after it has been 18-21. Not a huge difference, and I won’t claim for sure that it’s all from the fan (for instance I also put in synthetic diff. lube around the same time). But for $65 and a few hours of work, why not give it a shot?
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