I recently installed a Lincoln Mark VIII e-fan, controlled by a DCControls FK-50P on my '99 F-150 4.2 4x4.




Parts:

I picked up a '93 Mark VIII fan on ebay for $60. This is a monster fan which can move a lot of air. It can also suck a lot of juice, which is why I chose the DCControls FK-50P controller with its soft-start and variable speed features. I added the fan speed indicator light kit from DCControls to give me some idea how hard the fan is working (total, a little less than $200, shipped). I also picked up a new Ford 4.2 shroud on ebay ($40), so I didn't have to modify my original shroud.


Mounting the Fan:

Un-modified, the Mark VIII fan shroud is about the right height for the F-150, but is only about half as wide as the F-150 radiator. Because I wanted the fan to pull air through the entire area of the radiator, I extended the Mark VIII shroud on each side. These extensions mount the fan to the factory F-150 shroud. They also act as an inner shroud, forcing the fan to pull all its air through the full width and height of the radiator for maximium cooling.

I started by cutting away most of the Mark VIII shroud. I left a lip on the top to mount the fan to the F-150 shroud, and shaped the bottom to fit the bubble for the stock fan on the F-150 shroud.




On the 4.2, the back of the fan motor can't protrude much (less than 1") past the back of the F-150 shroud. Believe it or not, there is less room between the radiator and the water pump on a 4.2 than there is on a 5.4.

Test fitting the fan into the F-150 shroud ...




I made the shroud extensions out of aluminium road sign panel, cut out with a jigsaw and bent in a vise. I used cardboard to first determine the shapes I needed, and used the cardboard as a pattern to cut the aluminium.




Because everything is plastic, I used a lot of tabs/screws to spread the load




In a further attempt to stiffen everything up, I used double-sided moulding tape along with the screws when I fastened the shroud extensions to the fan.




Completed shroud extensions...






Fan mounted into the F-150 shroud, ready for installation...






With the fan installed, you can see how close the back of the fan motor is to the bolt for the clutch fan (capped w/ a rubber cap), although they are offset by about an inch.

 

Installing the Controller


In order to reduce heat in the controller (thus increasing life), DCControls recommends keeping the wires from the battery to the controller as short as possible (less than 5').. With this in mind, I bent up a quick bracket to mount the controller to the bottom of the battery tray.

Bracket ...




Test mounting the controller from the bottom of the battery tray ...




I built a harness for all the e-fan wires, to keep the wiring neat and secure. The two lugs in the center go to the positive battery terminal, one for the controller, w/ a 2A fuse, the other for fan power with a fuseable link provided with the controller. The single lug on the right goes to the negative battery terminal, with the blue wire going to the AC clutch wire. The coil of loom on the left is the temp sensor, which goes to the radiator. The connector on the lower right plugs into the fan motor.




The FK-50P Controller comes set for a 180 deg thermostat. A small screw adjusts this temp, with each turn changing the temp 3.5 degrees. I turned the screw 3.5 turns clockwise to adjust the temp setting for the 192 deg thermostat in my truck.




Controller mounted in place. The small black wire running from the output terminal is for the fan speed indicator light.




The temp sensor gets slid between the radiator fins on the outlet side of the radiator. My only complaint w/ the controller is that I sure could have used a couple feet longer wire on the sensor. The prefered location for the sensor is closer to the outlet hose.




The AC clutch wire is a gray w/ white stripe wire which can be tapped at Connector 119, located on the firewall, near the battery.




When connected to the AC clutch wire, the controller will turn on the fan at 50% power whenever the AC is on. I wanted the ability to turn off the fan when running the AC at highway speed, so I installed a switch in the wire running from the AC clutch wire.

The white 3-pin connector connects a loom (not shown in the previous wire harness pic) which runs 3 wires (2 for the switch and 1 for the fan speed indicator light) into the cab.




I mounted the switch to the radio surround. Blue light indicates AC compressor and e-fan are on.

 

Installing the fan speed indicator light


The fan speed indicator light is a single light which changes color as fan speed changes. The light is green when the fan is off, red when the fan is at 100%, and varying shades of yellow at speeds in between.

I mounted the light next to the water temp gauge on my A-Pillar gauge pod.




The light has three wires. Yellow for switched power, blue for ground, and black to the controller. Since I already had switched power and ground in the pod for the gauges, I spliced into these wires in the pod. I had a spare pin on the connector for the gauges, so I added the black wire to the controller to this pin.




Fan off ...




Fan at 50% (AC on) ...




Fan at 100% (or as in this case, fan on w/ ignition off)




Final touch of the mod was to transfer the Mark VIII fan warning sticker over to the F-150 shroud.




Notes on the mod

I've put about 1500 miles on the e-fan, and it's worked flawlessly from the first time I turned the key. Maybe a little better mileage, maybe a little more responsive motor, but definitely a much quieter truck. The lack of fan noise is great! The truck runs at the same temp as before the mod. The e-fan almost never comes on, and when it does, it's at less than 50% speed most times. The soft start and variable speed features of the controller work well with the power hungy Mark VIII fan.

 

As usual, another great article from you! Good job man!

 

Nice write up! I wish I had talent to do this stuff.

 

Nice, I just wish I had the time/get lucky at the salvage yard to do it.

 

Thanks guys ...

Takes no talent to do something like this ... if you can run a hand drill and a hand jig saw, you're in

 

Very thorough and inginuitive! My install was much simpler and less efficient but that was what was available at the time.

 

Can I bring my truck to you to tinker with when you run out of ideas for your own???

Yet another article to add to my "must do" list! Thank you so much for your work.

 

This mod was really all about tinkering

I don't see myself saving $300 of gas because of it. Performance ... come on, it's a 4.2 it's never going to pin you to the seat. I also have some reservations about the reliability compared to the bulletproof factory system.

That being said, my truck is sort of a hobby to me. Doing stuff like this is a great release ... soothes the soul

 

Very nice. I like the OEM-retention with the stock shroud, but I do prefer my dual 16's sitting on the radiator. That controller and A-pillar light is ingenious! Great write-up!

 

Fairlaner,

Do yourself a big favor and contact Mike at Madenterprises and have him send you his a/c switch. I put one on my truck and the fans only come on when the a/c needs it,like at low speeds, idling, etc. and you don't have to remember to turn on a switch. It works flawlessly. Wire it from a 12 volt source thru the switch to your a/c signal wire on the controller. It mounts on the inside of the a/c condensor near the hot line inlet. Mike will explain it all. He's great.

 

By the way: where did you get the light?

 

Thanks, Raptor It's nice to be able to get temp and some indication of fan speed in one glance. I kept the stock shroud because I wanted the fan to pull air through the entire radiator.

Thanks for the tip, King. Sound like something worth checking into. In my way of thinking, to get any benefit out of an e-fan you want it to run as little as possible. Flipping a switch is also tiresome and crude.

I got the light from DCControls for $10 (I don't know why they don't just include it w/ the controller kit). It has a glitch in that at speed (above approx 35 mph) with the fan off, the green light goes out. I'm assuming it's due to the air flowing through the radiator spinning the fan. When the fan comes on in this situation (AC is on), the light is red instead of yellow (green portion of the light is missing). I'm guessing some kind of diode would solve the problem. It works great at low speeds, which is the only time the fan should be coming anyways.

 

That makes sense about the light, because I have small light hooked to mine that only comes on when the fans engage and I noticed that it glows a little at speed. I guess the fans become small generators. I read a thread here somewhere about hooking a diode to it and it stops that from happening. Nice write up and a nice clean job. Let me know if you try that switch and how it works for you.