Here is the official tech write up for my electric fan install.
Until I get it in and 100 percent wired up the way I want it (couple months from now), this will not be complete. I'm going to update it along the way.
As with most things I do related to my truck, I researched, researched, and researched some more. I read just about every thread on electric fan installs on this site (including the crappy ones), plus a bunch on other internet sites into other vehicles (including the crappy ones). This research is what pointed me in the direction to get the parts I did. I asked alot of questions, and bothered alot of people. But I dont care.
All pictures are hosted on Superford, link is in my sig.
This thread got me excited about doing it, and has a TON of knowledge ant links to other threads in it. BOOKMARK!
Expectations/Reasons for doing it:
My truck gets 9mpg city, driving like I stole it. I'll see what I get when I'm done. Most people claim increased mpg of 1-2mpg, and better throttle response. Plus I get to add another switch in my truck. Switches are cool.
Here are the supplies I got. I might not use all of them but I got some stuff in case I wanted to use it during the install.
New set of crimpers/cutters/strippers since my 3 dollar hamfest "deals" suck major ass. Project box which will be watertight and house all the relays/controllers/fuses. This will be under the hood somewhere near the radiator. Grommets for said watertightness, fuses, diodes, fan controller, solder, 85 amp continuous duty relay and fan controller.
Here is the fan controller I used. 60 dollars from Advanced Auto Parts Imperial/Hayden 226204. It was out on the floor by the electric radiator fans they sell.
I also got the fan controller that Brian Solderblom used in his project (226203, 20 dollars, simple adjustable thermal switch), but he had to add all the other wiring that the more expensive controller included with it. If you open the full size image and tilt your LCD screen you can see the label and what each wire is for. All I have to do is connect each wire to what it tells me to connect it to and it works. Sorry its so bright.
So I have most, if not all of the stuff needed, besides basic wire and a fuse holder or two. I havent fully decided how to wire it up so I'll get those items as I move along.
Before the project, I had the stock 460 mechanical fan behind a 3 core Modine radiator without a fan shroud. In Florida heat with the AC on my stock temp gauge never even got to the middle. Yea yea I know I need a real gauge...in due time.
I read the whole Taurus Fan thread a few times, and from what I gather, a simple 2 speed taurus fan from a 3.8 liter engine would be more than sufficient for my needs. However since nothing I do has the goal of being "adequate" (except calculus...god I hate calculus) I wanted the biggest/cheapest fan I could get. The lincoln Mark VIII at a claimed 4000+CFM. Alas there were no Lincoln Mark VIII's in my local yard, so I decided to get the next best thing. Nor were there any Windstars to get the dual fan setups from. This left the Taurus or T-bird fans.
Seeing as how my cooling situation is more than adequate, a 2800CFM Taurus fan sealed up to the radiator seemed to also be more than adequate. I walked by many Tauruses with 3.8's and fans but something told me to keep going through the whole Ford section. I passed 2 T-birds in good condition with their fans, and decided to come back if I didnt find a Lincoln or Windstar. I remember hearing the T-bird fans were comparable to a Mark VIII fan, or if not, at least superior to a Taurus fan, so I figured this is an option to get.
On the last row of Fords I walked by this:
A 3.8 liter Taurus fan waiting for me to unplug it and walk away. So I decided to get both the Taurus and T-bird fans and sell the one I didnt use.
Not finding anything better, I walked to the Thunderbirds. They were like brothers, looked the same, sitting side by side. One was a 1994, the other was a 1998.
Here is what it looks like from the side so you know what it looks like walking by. Cars with mechanical fans generally have bigger shrouds.
The T-bird fans are only held in with 2 bolts. I got about a foot of harness with each fan for splicing.
Here is the Taurus fan. 16 inches blade tip to blade tip.
Here is the T-bird fan. 18 inches blad tip to blade tip. I also like the width of the fan blades at the tips. Not only is this the fastest spinning part of any fan/propellor, its much wider. I assumed it would move alot more air than the Taurus fan, especially considering its 2 inches bigger.
Note that both fans are from similar year cars with the same size engine.
Taurus fan 22 inches wide at the shroud.
T-bird fan 22 inches wide at the shroud.
Taurus fan 17 inches tall.
I dont have a picture of the T-bird fan vertically but its square, unlike the Taurus fan, so its ~22inches.
Taurus fan depth. About 5 inches.
T-bird fan depth. About 5 inches.
The only difference I can tell is the T-bird fan is simply taller than the Taurus fan, which does not matter with the big radiator I have.
On to the mechanics of the install.
Remove the 4 fan bolts holding the fan to the pulley.
Remove the fan. It might not want to come off depending on how long its been since it was removed.
Put the fan bolts back in. The pulley is held on by these fan bolts, so its important they go back in.
Now to test fitment of each. I previously hooked each fan up to a 12V power supply to see what each one did. They both seemed similar. I did not notice a big difference in air flow/speed/noise between low speed and high speed settings. I did not notice a big difference between the Taurus fan and T-bird fan either. However the one observation I made was while the velocity of the air between both was similar, the T-bird fan had more TOTAL air moving since it was wider. I had it sitting on a guitar amp, open on both sides, and the column of air it was blowing up was noticably bigger.
Based on this it confirmed my decision to use the T-bird fan.
OK it doesnt fit.
Top down view, you can see its too deep to fit. This is most likely due to the extremely large radiator I have compared to stock
Taurus fan fits perfectly.
Here it is held to the drivers side of the radiator, which is the same position the T-bird fan was in, in the above picture. Notice the plethura of room.
Here it is just for kicks right in the middle of the radiator. Still alot of room.
Someone explain this to me. This is about an inch thinner, but my measurements (shown in pics above) show just about the same thickness.
Read above statement about me aiming for "adequacy" and you probably know I decided to MAKE the T-bird fan fit. Which wasnt that big of a deal anyway...
I checked the space between the fan and the edge of the fan shroud on its longitutinal axis, and there was about 1 inch space, so a half inch of material removal seemed fine.
Here is is flush to the drivers side where it gets the most clearance, and seems to be fine. It's tight but I dont think I'll have any problems.
This mounting tab now stuck past the plane of the fan shroud edge, and it hit the side tanks of the radiator, which are also thicker than the radiator itself. This created a gap between the shroud and the radiator, which moved the fan slightly closer to the engine. I cut this stupid thing off and now the fan is flush to the radiator for a better seal, and there is a little bit more clearance between the fan and pulleys. Hooked it up to my battery on the truck and the fan ran just fine without intereference.
With the fan trimmed to fit, I moved onto the wiring.
I put the control box between the passenger side headlight and radiator. I havent mounted it yet because I will be adding more things to it shortly. The first wire I ran was the IGN ON wire. This allows the fan to run whenever the ignition is ON.
This is the most convenient place I found to tap into an IGN ON source. The green wire is going to my fan controller, and the blue connector is the tie-in. Its a blue/white wire on the EEC relay. Not sure which. I am going to seal this connection up better when I figure out how. I never liked solderless connectors.
I try to check every step of a wiring job I do so I know it is working, and I dont spend hours later backtracking if something doesnt work. Here is the wire (now yellow) going to the fan controller with the IGN ON. Sorry for the glare but trust me, its getting +12V.
Without any big heat shrink I resorted to electrical tape for the splice into the pigtail to the fan. Im using 8 gauge wire so if I go to a dual Taurus fan setup later I'll still be ok.
Here is the 85 amp continuous duty relay. Manufactured by Cole Hersee (Boston, MA). Theres 2 numbers on it. I think the model # is 12V504M, but above it, it says 24059. It's mounted to a radiator core support bolt. The the coil that activates the relay does not ground itself to the case, therefore you must ground one of the studs.
Here is where I put my temperature probe. This is the hottest part of the radiator (so I'm told), and I have the fan controller set at the highest temp limit so the motor can heat up. Because the probe is at the hottest point of the radiator, I dont have any adjustment left. I might move the probe to a cooler part of the radiator so I can back the controller to a lower temp setting and get some adjustment back. We'll see, I'll play with it later.
AC clutch wire is installed and works fine. This green wire comes from the fan controller. It is tied into the black/yellow wire on the AC clutch harness.
This is where I routed the wires to the fan. Gonna put split hose around it when I get a chance.
Bottom up view...
Put about 2000 miles on it, havent noticed any mileage increase. Possibly even a loss in mileage due to my AC being on constantly in the summer heat, even with adequate airflow through the radiator such as on the interstate. 2 Taurus fans put a good load on the alternator, so it possibly negates any mileage increase I would have realized. In percentage of total load on my engine, my mechanical fan was probably much less than most Broncos (percentage wise). I have 37's and stock gears so my motor has alot of work to do to get me moving, so the lack of fan is not as noticable due to my horrible gear situation. I will update my mileage numbers when the weather cools down and Im not using my AC.
I also decided to put in 2 Taurus fans instead of the single Thunderbird fan.
This was because I noticed the temp gauge going higher than normal. It never overheated, but it took a while for the needle to go back to where it normally stays after a hard run with the AC on.
Seeing as I havent towed anything or done any real hard work with my truck in extreme heat with the AC on (it hardly works), I saw room for improvement. My goal is to be able to tow heavy loads, or do multiple pulls of my stuck friends trucks while the AC is on etc. Dual Taurus fans were the answer.
34.5 inches after cutting the shroud.
My radiator is about 28-29 inches so I used cardboard to make a template and see where I needed to cut.
Rough cuts made, I had to tweak it and make some more minor cuts to get it to sit level where I wanted it.
My wiring job. I dont really like it, but I kept the longer 8 gauge wires intact until I figure out what I'm going to do with that fuse box I got from the Thunderbird.
Here is the mount. A 1 inch wide strip of aluminum bent to follow the countours of the shroud. It sticks behind the lip at the bottom of the radiator core support, and the lip holds it in place so it doesnt go back toward the engine. The top part is bolted to the lip of the radiator and it is the only bolt that holds the whole fan assembly in. Remove it, and you can remove the whole fan assembly.
However its not very supportive, and I think it needs extra support, especially if I go off road with vibration and flexing. I think the mount might fall out if I hit a good enough bump.
P.S. No making fun of my battery tie-down allowed.
Update2: The 85 amp relay seems adequate to handle the current of 2 fans. One problem I ran into after a few months, however was related to wiring. The wire gauge I used was fine, but the cheap connectors at the relay were not adequate to the current flow. The nut on the stud holds the connector down on the nylon spacer that keeps the stud from moving around in the relay, and insulates it from the metal case of the relay. The low surface area of the ring terminal I used would heat up in extended operation, and eventually melted the plastic of the spacer. The pressure from the nut pushing on the connector mushed the ring terminal into the melted plastic, which, after hardening would be between the nut and ring terminal itself, thereby insulating it from the stud.
To fix this, I got another nut (5/16 fine thread IIRC) and sandwiched a higher quality ring terminal between them. This allowed current to flow to the ring terminal through both nuts, and therefore both sides of the ring terminal, doubling the surface area. So far it seems great.
Update3: While the fans were out of commission for a week or so, and I couldnt fix them due to my broken arm, I drove my truck anyway since all the trips I make are 15 mins or less. I didnt use my AC during this period to avoid overheating. With NO fan's running, and moderate stop and go driving in the hot Daytona city driving, I never had an overheating problem. Driving at 30+ mph is more than adequate airflow to keep the 460 cool. I even flipped on the AC, and as long as I'm moving, no problems. This is a HUGE deal, I think the fans dont even need to be on if the truck is moving, with or without AC. That would present a great opportunity to change my wiring to keep the fans off more, when not needed.
89 XLT 460