I figured the fan that Chrysler installed grabs enough
air to cool a few engines. The thermal clutch fan is suppose to allow
the blades turn at a certain percent of the pulley speed. That is
true unless the fan clutch senses a high temp and then turns almost as
fast as the fan pulley. I decide to replace the fan with an electric
fan with an electronic thermostat. Back to JC
Whitney for a fan. They had a 16" fan with electronic thermostat
for $99. Checking around I found the price was very good. Now
for the install.
Taking off the metal holder for the radiator (see instructions for removing this under trans cooler) you get some extra space by moving the radiator forward. You need to loosen about 5 bolts on the power steering pump. Two are hidden, one in bottom front, one in the bottom back. The tensioner bolt is a 13mm and you need a small socket wrench to loosen it. You have to loosen it a lot to get it over the power steering pulley. Don't remove it yet. You have to remove the 4 fan bolts. Use the loose belt around the water pump pulley to move it into place. Pull the belt tight to hold the pulley and loosen each of the 4 bolts. Take the whole fan and shroud off. Make sure you don't lose any of the rubber edging on the shroud.
You can now replace the water pump pulley bolts and retighten the belt (not to tight, watch it). You can then remove the top metal radiator cover. Place it across to the side, watch the windshield. I decided to place the fan on the shroud. This should allow air to be pulled from the entire radiator rather then just the 16" area covered by the fan. This fan has plastic clips to hold the fan but since I had to place the fan inside the shroud I had to place the clips backwards. Since the clips didn't lock in this position I used metal wire to keep it from sliding off. I purchased 2" air conditioner foam (for excess space when installing a home room air conditioner) and filled the space in-between the shroud and fan. You might try other ways to install the fan and try foam pipe insulation for the space. You want the space filled so the fan pulls air through the radiator. Make sure the foam doesn't hit the radiator and keep air being pulled from the entire radiator. I had to cut some off. As you see from the picture you don't have much space there. I don't know what a V-8 spacing would be or if this would be enough to cool the engine even in the cooler months.
The instructions from the fan leave much to be desired.
* (see Stupid, Stupid, Stupid below) Since the company must purchase this
item from a quality company but not leave any logo, the instructions are
copies of some of the original instructions. The fan came in a plain
white box. The instructions show a blurry shot of where the thermostat
is suppose to go and no reason why the white wire (for the air clutch)
goes to ground. After installing the shroud, I snipped
one of the radiator fan shields to run the fan wire through and avoid it
getting caught by any of the belt items.
This shot shows the small space from water pump
bolts and fan. You can see the fan wires through the shroud top
in the shot. To wire the fan I pulled the power from the battery
(the instructions say don't do it should the thermostat fail closed and
on) I added a fuse
to the battery positive terminal which then went to the power of the
thermostat. I also hooked the wire to the driving light to
this connection as that fuse is very close to the lights leaving a number
of feet of wire able to short out. This main fuse is a 20 amp, 10
for each of the items. The electronic thermostat has an attached
temp sensor that gets inserted into the radiator fins. At least I think
that what the picture shows. A wire needs to be connected to a "keyed"
power supply, allowing the fan to operate only if the key is on.
This keeps any car alarms quiet. Two separate ground wires need a
connection. I found one screw holding a plate above the headlight
opposite the battery. The other was a bolt to the ABS computer, I
cut the ground connector to fit the bolt. The electric thermostat
also has a white wire, it is suppose to be connected to the air conditioner
clutch. This wire came attached to one of the grounds, more
on that later.
The test was on. It is Jan. in NJ so the 30 degree weather keeps the fan off at all times except stopped for a few minutes or climbing steep hills. Even on hills it move only a hair above the normal position. I don't know if I will need to change the thermostat in the summer to a 180 degree. I'll wait and see. The fan is very quiet and the Jeep is very quiet when starting cold. It also heats up a bit faster (no fan to cool the radiator). I haven't seen any big gas mileage improvements but the temp is colder then a week ago. I have seen that in cold weather the computer doesn't show 8 mpg driving down the street the first few miles. It actually hit 12mpg. As you see in the photo the factory fan really digs into the air and pulls a lot. It has to take some power to turn that especially when it's cold.
Well now it's later, April 1st. The electric thermostat has died and it's now two calls to J.C. Whitney. They say "no problem" a replacement will be out in 10 days or so. Have to call again! The electric fan works great in the cold. The engine never went above normal (second notch on the temp gauge). Even in traffic with the fan off it barely moved much unless I was stuck in heavy traffic. In the spring (85 degrees these past few days) is a different story. The highway is fine without the air conditioner on. Turn on the Air and you better turn on the fan. The white wire connection that is attached to ground, I snipped off and covered the exposed wire from the ground. I will run a wire from the air conditioner clutch to the snipped off connector. It doesn't take any power draw so there should be no power drain on the air clutch connection. If you want a switch to turn on the fan, that is where a positive power lead should go. If you take that route, you must add a diode from the wire coming from the air conditioner clutch so any juice from this "always on" fan switch doesn't activate the air clutch relay (or blow that fuse trying to activate it).
In traffic, without the fan the engine will go to 210 degrees in 5 minutes. My temporary fan switch cools the engine down with no problem. I'm wondering what would happen with the Air on in heavy traffic.
(Stupid, Stupid, Stupid) I removed the 195 degree thermostat in April, now in normal driving the Jeep hits the first notch on the temp gauge, a good 15% cooler. I will have to change the thermostat back in Oct. as the heat is not as good. With the original fan out of the way it only takes 20 min. to change the thermostat. A plastic hose on the radiator drain cached most of the radiator fluid. THE STUPID part is the J.C. Whitney instructions for the thermostat. I finally got a replacement electronic control. My other control started to turn on an any time. I replaced the unit quickly but found the same problem. The fan would turn on and then off after 15 seconds. I got a photographic thermometer and installed it in the fins of the radiator. First, the radiator fins do not get as hot as the radiator. This kept the thermostat off until the engine got well above 210. When the fins did get hot enough to set off the control switch the fan would turn on. As soon as the fan turned on the temp between the fins dropped to 90 degrees in 14 seconds. Hence the probe would think the radiator is cooled and shut off. That's why the first control unit didn't work right, the instructions were non-existent. To install this correctly you must install the probe by the very last fin touching the radiator itself. I have a bit of insulating pipe foam stuffed in there to keep the probe against the radiator part and bouncing around while driving. Now it works fine. I still had to adjust the control adjustor to turn on the fan at just a hair above 210 degrees. I' m thinking that the probe belongs inside the radiator hose, I have seen some advertised with that option. That's the story. I will hook up the Air Conditioner relay to the white wire with a diode as that wire has a switched wire to manually keep the fan on. Without the diode, the manual switch powering the fan could activate the clutch.
GAS MILEAGE: without the Air on the computer showed 22.5 mpg average for the first time ever and a nice 29mpg while straight hwy at 60 MPH. I have noticed the mileage improvements. How much is the electric fan against the muffler, I can't say. I'll have to keep the fan on while driving home and check the gas mileage.