Finished up most of the Taurus Fan Swap installation this weekend. Got a few pictures and some instructions for you guys.
Parts:
1. The fan (obviously). From a 3.8L V6 Taurus or some 3.0L Wagons. The difference is the fan motor - the fan shroud and blades should be the same. Most sources rate this as 2500CFM on low speed and
4500CFM on high speed.
2. 80.5" 6-rib belt. At least, that's what was needed for my 2000 4.0 Auto XJ with AC and power steering. Always remove your old belt, route a wire or string as the new belt and measure.
3. (2) 40A relays with appropriate fuses, wire connectors, and wiring.
4. (1) 85A relay with appropriate fuses, wire connectors, and wiring.
5. On-Off toggle switch
6. On-Off-On toggle switch
7. Electrical tape
Tools:
1. 15mm socket, extensions
2. 15mm wrench
3. Grinder with cut off wheel, grinding dics, appropriate safety equipment
4. Drill with various bits
5. 8mm socket and appropriate wrench
6. Appropriate wiring tools
Procedure:
Step one: Remove and modify the AC bracket
I chose to cut off the the mount and bearing for the clutch fan. Some have gotten away without doing this - it wouldn't fit for me.
Remove the AC pump. Four 13mm bolts hold it down. Flip it over backwards. I unplugged the electrical to keep from stressing the wires. To remove the AC bracket, you will need to remove the two 15mm bolts holding it to the head, and one 15mm holding it to the block. There is also another long bolt with a nut on the back side of the bracket. Hold the bolt head with a wrench and back the nut off with your socket wrench. The bracket slides out toward the fire wall.
You could probably do this with the fan still on the mount, and the bracket out of the Jeep. You can see where the bearing is pressed in to the housing. The boss it is pressed into has several ribs. Using a 4.5" Angle grinder, cut around just behind where the fan mounts, then using a hammer and a drift, bang the bearing out. To make it look a little more factory, I cut the boss off flush with the rest of the bracket. This is hard to describe in text, but those of you with the bracket in front of you will get the picture. This would be much easier with a large (7") grinder.
Alternatively, you could cut this off with a sawzall without removing the bracket. Be sure you cover the alternator if you go this route.
Here is the new belt routing with that pulley deleted:
Step Two: Modify the alternator bracket
Install your new ~81" belt and you will see where it hits the alternator bracket. I used my grinder with a cut off wheel to cut that section of the rib off the bracket. It does not appear to effect the integrity of the bracket. Then, using the grinding wheel, I ground it down smooth and painted it. Re-install your belt and double check for clearance. This may take a few 'adjustments'. Repeat until you have sufficient clearance (~1/4")
Step Three: Make the fan physically fit
This can be tricky. With the stock shroud removed, you can see the tabs it locks into at the bottom of the core support. Cut these off flush with the rest of the core support - be careful of your radiator!
With the belt and bracket removed, I had a friend watch the motor while I revved it. My 4.0 moves forward ~1/4" and side to side ~1/4", but it seems to pivot around the water pump - where the fan motor is close to. Keep in mind when trimming your fan that your motor will move just a bit.
Now slide the fan in vertically and you can see it is too thick. Placing the fan motor side down, you can see that the sides of the shroud are taller than the ends. I used a piece of wood and a marker to scribe a line to cut the fan shroud down length wise so it would not be as deep. It still mounts to the core support and has plenty of clearance before it would hit the radiator. You will also need to trim a 'step' in the fan on the battery side to clear the frame rail. The transmission cooler hoses will be in your way as well. I cut about 2.5" off the bottom of the fan because it hung below the crossmember. This helped a lot with the transmission cooler hoses. The hose on the right will tuck forward into the cross member, the hose on the left will need another 'step' or a slot cut out.
Continue trimming your fan until it fits properly. You will have to mount the AC bracket first with the long bolt in if you want to use the long bolt. The long bolt is only 1/4" from my fan, but everything else is 1/2" to 3/4".
Step Four: Mount the fan
Slip the belt in place before you do the final fit of your fan - the belt is difficult if not impossible to install with the fan in place.
The factory shroud had two bolts that went into clip nuts. My XJ had two holes spaced closer together than the stock bolts. I moved the clip nuts to those holes. The Taurus fan already had holes in the correct spot - you may have to drill one or the other. Be careful if you drill the core support, the radiator is right behind there! Once you have it where you want it, cut it nice and even across the top.
For the bottom, I bent a piece of my hood left over from the vents and bolted it to the shroud, then bolted it to the crossmember. Pull the bottom of the fan in tight, but spin the blades by hand to make sure you haven't warped the housing.
Double check all your clearances and that the fan is securely mounted.
At this point, if you cut your AC bracket and fan nicely, this setup should look pretty much stock.
Step Five: Wiring your fan
Here is the wiring diagram I sketched out in Paint to help with this:
The green 'From Aux fan' will receive power any time the aux fan has been switched on - either by the ECU or by your handy manual fan switch.
Using two switches as pictured it will work like so:
Aux fan switch OFF will be Auto and Aux fan switch ON will be Manual.
Auto works like so: Taurus fan will operate at desired speed (UP = High, DOWN = Low) when Aux fan is switched on by ECU. Taurus fan can be switched off using the center position.
Manual: Will operate aux fan manually and Taurus fan at speed desired via switch. Can be operated without ignition.
For manual control to work, you must wire in manual control of your aux fan. Basically, set up another relay that trips power into the fan when you activate the switch. Use the 'low speed' diagram above if you need instruction. You can use a large butt connector or solder the connections so the power feed from the ECU will still operate the Aux fan as well.
I ran five wires into the dash.
1. To activate high speed relay
2. To activate low speed relay
3. To activate aux fan relay
4. Power tapped from the aux fan power (For auto operation)
5. Constant 12V (For manual operation)
I routed the Taurus fan wires behind the grille and chose to mount the relays by the battery to keep the wires as short as possible. The Aux fan relay is under the brake booster.
I removed the battery and ran the harness for the fan between the battery tray and fender. Connect all the wires, and always use an in-line fuse. I soldered all connections except the terminals on the relays. Always tape over your connections at the relays for safety, and use relays that include a mounting tab. Be sure your fan harness is far from the belt.
Mount your AC pump, and belt. Connect the coolant hoses. Connect and mount your switches, check again for clearance and double check all your electrical connections and you should be done!
Edit: If someone wants to post pics of a Taurus fan, I will happily edit them to show where I cut the fan. Would need pics of the side of the fan and the radiator side of the fan.
I'll likely edit this thread with any more info I think of or pis. Questions?