A little over a year ago I decided to convert my 4.9 I6 from an engine driven fan to an electric fan. I was trying to pick up a little more gas milage and power. Another consideration was the lack of cooling with my A/C at low speeds or idling in traffic. The gas milage only went up about 1 or 2 mpg, but the power gain was amazing, and the A/C works great at idle also. My engine reaches operating temperature faster and runs cooler in the Summer months. I have also noticed the main fan does not operate that often, and then only for short periods of time. The first time I put it on the highway after the conversion it surprised me. I was behind a car doing 65 mph, so I applied the normal amount of pedal to pass at 70 mph and wow, I looked down at the speedo and I was just passing 80 mph and still climbing. Normally my engine strained to make 75 mph, and it cleared 85 with no sweat. Since that time I am still amazed at the extra power this modification has given my truck. I decided to share this with you in hopes that someone with a simular truck configuration could benefit from my experience with this project. This was a difficult conversion due to the clearence restrictions of the I6 engines. Some areas I had only 1/4 to 1/2 inch of clearence. I also wanted to keep costs down as much as I could, and to use as many Ford parts as possible for out of town repairs etc...
Parts List:
1-16" Ebay E-fan (Main fan)(Later changed to a '96 Tbird 17.5" fan $20.00)
2-10" Ebay E-fans (A/C fans)
1-Ford constant control module('86 Taurus and some Mustangs) $5.00 w/ bracket
1-Ford triple relay block w/ relays('86 Taurus)$5.00
1-40A circuit breaker(auto parts store $5.00)
1-Waterproof fuse holder
1-Thermostatic fan switch(Flex-O-Lite $44.00)
Assorted wiring terminals, and butt connectors
Assorted wire #8/#10, and #14/#16 various colors
Assorted plastic wire loom, heatshrink tubing, and electrical tape
1-27 1/2" X 21 1/2" X 3/32-1/8 inch sheet aluminum(fan shroud)
10' 3/8" X 1/2" foam weatherstrip
assorted hardware
:a side note on the Ford constant control module,it contains heavy duty relays that are expensive and difficult to find:
To begin I took clearence measurements and transferred them to the fan shroud to determine the fan location.

Then I cut and finished the shroud and installed the fan.

I then made a trip to the local pick and pull for my Ford parts. When you get your parts you should get any brackets, electrical connectors, as well as at least a foot of the wire harness( They dont mind they're junk cars).
Next I set out to create the wire harness, but before you do this you will need to determine the best locations for the components. These are the locations I chose.




After roughing in the wiring harness I wrapped it with electrical tape. I tested it for fit, trimmed excess wire, and added terminals, plastic wire loom, and factory connectors from the pick and pull.

All connections are soldered to prevent corrosion.
Next I installed the fans, hooked up the wiring and tested the system. All the factory circuits on the truck are isolated from the fan circuits by relays and fuses, so no damage can be caused by a short circuit in the fan wiring. This proved crucial after my cheap main fan seized up. It is also a good idea to use a heavier gauge wire in the fan power and grounding circuits, this helped me because the fan wires burned up but my harness was unharmed.



Here is a schematic wiring diagram.

I installed a LED indicator lamp to the main fan circuit to monitor it's operation.

The system has been relatively trouble free since the install.
The only problem I experienced was a failure of the cheap main fan. I am not satisfied with the quality and the noise of the A/C fans and will be replacing them with Ford fans from the pick and pull at a future date. If anyone would like any other info you can reach me by PM, e-mail, or MSN chat. I would also like to note that you should have at least a 95amp alternator to insure the proper amount power for the system.

Robert your setup is so trick with that Ford fan controller-- I'm jealous.

Can you give a brief description of how the circuit operates? Which conditions turn the fan on/off, which speed on the fan (hi/low), etc?

Yeah no kidding Reps to Rob

Skandocious said:

Robert your setup is so trick with that Ford fan controller-- I'm jealous.

Can you give a brief description of how the circuit operates? Which conditions turn the fan on/off, which speed on the fan (hi/low), etc?

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Fans only run 1 speed and the main fan is set at 193*on 170* off, A/C fans switch on with A/C.

Very nice. I've been giving some serious thought to switching to electric fans. Once I get my engine rebuilt and the front clip switched out, I'll have to pick your brain. I got the mechanics down, but the electrical bumfuzzles me.

Bob said:

Very nice. I've been giving some serious thought to switching to electric fans. Once I get my engine rebuilt and the front clip switched out, I'll have to pick your brain. I got the mechanics down, but the electrical bumfuzzles me.

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No problem Bob. This was a bit of a head scratcher for me too.

Thanks guys!

wow, thanks a lot for the write-up. very tempting

Good job! I'm going to do a similar type of fan conversion on my Expy once the 4.6 DOHC and turbo is running.
Just a heads up to others doing the same thing, the Geo Prizm uses a packaged relay set up that will work great for this type of install. I use one in my Mark VIII to power my headlamps and driving lamps. It is a very compact set up that sits next to the battery of the Geo and next to a fuse/relay box. It is about 5" long and 1 1/2" wide, containing 3 relays and a 40 amp fuse. I hope this helps some of you.

Moto Mel said:

Good job! I'm going to do a similar type of fan conversion on my Expy once the 4.6 DOHC and turbo is running.
Just a heads up to others doing the same thing, the Geo Prizm uses a packaged relay set up that will work great for this type of install. I use one in my Mark VIII to power my headlamps and driving lamps. It is a very compact set up that sits next to the battery of the Geo and next to a fuse/relay box. It is about 5" long and 1 1/2" wide, containing 3 relays and a 40 amp fuse. I hope this helps some of you.

Click to expand...

Lets see some pics Mel, and thanks!!!

Moto Mel said:

Just a heads up to others doing the same thing, the Geo Prizm uses a packaged relay set up that will work great for this type of install.

Click to expand...

my wife has a 97 geo prism. if someone tells me what they need a pic of, and where it is, i can take some pics so other members know what to look for at the junkyard.

also, geo prism's should have all the same parts as a toyota corolla

Thanks for the write up and the parts list radialarm. I'm getting ready to change out my water pump in my 97 4.2 which has a slight leak. While I'm at it I'm going to add some underdrive pulleys from Troyer performance and a goodyear gatorback. Lastly I'll get rid of that heavy metal fan and I'm looking for some cheap junkyard electric fans to add to my setup just like this. Again, nice write up and pics, they're very much appreciated.

great write up. I have been pondering electric fans for a while now, thanks.