Can you change 3 prong cooling fan wires to 2 prong

SOURCE: 1998 Jeep Grand Cherokee 5.9 V8. Radiator cooling

Since the 5.9 electric fan motor cannot be purchased anywhere but from the dealership and for several hundred dollars, here's how I replaced mine. 1998-2000 Ford Crown Vics, Lincoln Town cars and Mercury Grand Marquis have exactly the same electric motor in them with a different style 3 wire connector. The part # at Autozone is PM9069, comes with a lifetime warranty and cost me 119.99 on 8-30-08. The only trick is getting the connector from the junkyard from one of the above vehicles. I got one from a Grand Marquis and a second from a Lincoln 100 feet away (I have 2 5.9s and I'm planning for the future on the second one). If you're really pressed for cash, take the motor from the junkyard too and hope it works. Watch the Lincolns as they have the correct motor and connector on the driver's side of the radiator and a second motor on the passenger side of the radiator which only has a 2 wire connector. If you get this connector and/or motor you'll only have hi speed or low speed depending on how you wire it, but not both. I cut the connectors off with about 6 inches of wire. The 2 connectors cost me $5. Once you've removed your old fan motor from the fan blade and the shroud and you have it sitting on the top of the radiator still plugged in, sit your new motor with the junkyard plug in it beside the bad motor. The center wire is the ground. I think the right wire was the high speed and the left wire was the lo speed. The high speed wire is the red with white stripe wire. It doesn't really matter as the Lincoln wiring is a different color. As long as you cut the left or right wires at the connector on the harness side of the connector ONE at a time, strip it and attach it to the same left or right stripped wire on the connector on your new motor, it works perfectly. At the very least, put a piece of masking tape labeled either left or right on the two wires since it's easier to cut all three and then solder with the old motor out of the way. You need to solder these wires as there's a lot of juice going through them. Wire nuts will get corrosion in them and you'll have problems a couple years down the road. A pencil soldering isn't really hot enough. You need one of those trigger ones that get real hot as these wires are good size. If you happen to mix up the wires on your electric motor, it won't hurt anything. When the sensor in the driver's side upper radiator hose turns on the fan to low, it will always run on high speed instead of the intended low speed. The high speed sensor in the passenger side lower hose will basically not be doing anything because it would actually be turning on the low side of the motor. The high and low are seperate in the motor. You do not need the low side running to get the motor onto high. I've heard this debated and ran my new motor on high and low seperately with jumper cables to find out before I installed it. The only other consequence of incorrect wiring is when the AC is on which normally runs the fan on low, it will now run on high. It doesn't hurt anything and cools better, but it is noisier. I considered wiring it backwards on purpose to get more cooling earlier, but finally decided to wire it correctly and let the sensors do their job. You won't have any problems as long as you still have the original 150 amp alternator in there(56041 394AA on the silver sticker). You can't buy the 150 amp alternator at the parts stores. If somebody's put in a 90, 117, or 120 amp you could have some dimming when the fan kicks on. The 136 amp which is the biggest the parts stores list for a 96-98 grand cherokee would probably be okay. When the 150 amp ones go bad, it's fairly simple to put new bearings and brushes in them. The hard part is getting the pulley off. If you still have the factory thermostat in your 5.9 (it runs 210 on the temperature guage ALL the time), you'll notice your electric fan never shuts off. That's probably contributed to these fans burning up and seizing. The low side kicks on around 200 and the high side about 215. So with the original thermostat, the fan is on low as soon as the thermostat opens and never shuts off. Both my 5.9's had the fan running all the time when I purchased them, one with 22,000 and the other with 48,000 miles. Of course I ran to the dealership for a new sensor in the top radiator hose for one of them which did exactly nothing to fix the problem. I finally unplugged the harness from the low speed sensor, filled the sensor and harness connector with grease to keep out the corrosion, zip tied it to the power steering hose, and I've run both of them for 8 years or so with just the high speed sensor cooling things down. When the water pump went bad in one of them 2 years ago at 160,000 miles, I put in a 185 degree thermostat as well, plugged the sensor back in, and now it works perfectly. By the way, the 25 degree drop in temperature really cut down on my heat in the winter. If you live north of I-80 or so, I'd leave the original thermostat in there. Or go to a 195 degree thermostat. That's going to be real close on whether the fan will be running all the time or not. It should be okay, but you'll have the fan coming on every two or three minutes in city driving. What really wears these fans out is miles. When you're driving down the road and the fan is not running, it's still spinning like crazy in there from the air going through the radiator, and that's accumulative wear on the bearings. Back to the soldering, if you want a neat looking job, slide some shrink tubing on the wiring before you hook them together and shrink it down when you're done or use electrical tape. I ended up with 8 inches or so of excess wiring which I have zip tied to the radiator support just below the radiator cap. Now you've got a fan motor with a lifetime warranty. If it ever goes bad, you get a free one. Hope this helps other 5.9 owners, because I searched in vain for 3 months for a way to fix this. It wasn't until a Jeep mechanic mentioned certain Ford big cars had a motor like the bad one I was carring around that I got pointed in the right direction and found the years and models on my own. I was driving it around without a fan because I live in the country without much traffic. If you live in the city, you couldn't do that or risk melting the engine down.

SOURCE: i need a radiator cooling fan motor for a 2004

funny, dealing w/ same problome today...Driving w/ heater on while 115 in Arizona is no fun.......DEALERS ARE NEVER THE SOLUTION FOR JEEPS!!!!!! $80...ebay make sure 3 prong...also 4th bolt on fan sucks here's a how to do..... http://www.jeepforum.com/forum/f310/04-wj-special-edition-overheating-1027069/
Also don't cut hole underneath headlight on 04....relays are in box...do a jump from plug to battery!!

Dale Farr

• 78 Answers
• Posted on Jan 15, 2011

SOURCE: Have problem with the trailer hook-up wires. Have

most of the wires are only for lights & will only work as such. the best thing to do is go to you local car parts place & pick up a converter that plugs into the 7 wire connector & changes it down to the four wire. It's usually less than $10 & saves a lot of time.

SOURCE: cooling fan does not come

The fan runs of a temperature sensor .You can get a schematic for free at your public library from Chiltons online .