If you've read any of my past posts you'd know that my 04 Liberty has a history of transmission overheating but typically on the trails not while towing. I thought it was due to my poor driving habits (i.e.: driving in 4WD Hi in Drive with O/D on ) Even in 4WD Lo in 2nd gear with the O/D off it overheats.

Today it happened again, my Transmission Overtemp indicator came on while on a mild trail in mild weather. I took a quick look under my hood with the A/C on too and noticed the electric fan wasn't moving . So I checked the voltage at the electric fan...none . So checked the fuse box under the hood...the 40A fuse was blown . So I swapped out the fuse for the one from the power windows and still no electric fan movement and the wiring to the fan was getting hot . Before the fuse blew again I pulled it out. Tomorrow I'll have to pull out the electric fan & shroud and have a close look at the fan. I have to wonder just how long the fuse was blown.
Does anybody know what DC resistance I should measure on it?


I'm curious about something, the electric fan within the 04 Liberty is a two speed fan but I can find nothing in the FSM that explains the speed selection. The FSM does explain that the PCM decides when the electric fan should come on and makes that decision by inputs from the coolant sensor, battery tray temperature sensor, A/C selector switch and vehicle speed. Maybe the fan speed selection depends on vehicle speed.

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my trail & highway ride (and occasional tow rig)
04 Liberty Sport with a 2.5" lift, ProComp 245/75R16 AT's and two Hella700FF lamps (more accessories to come)

my trail queen
95 YJ with a RE 4" lift, 33" ProComp Extreme's, M8000 Winch, Lockrite Locker up front, Super35 in the rear and 4.88 gears

Take the fan motor apart and clean the motor brushes.It only takes a light film of muddy water to keep it from working. You have to bend the tabs on it to get it apart. But I have had to do this a couple of times.

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2003 KJ Renegade, 5 speed, frankenlifted,Al's a Arms 4.5,Moabs 245/75/16 BFG KM2's, custom rock rails, full Mopar skids, Hella ff220 lights,Hd cooling,Front DTT,Riddler diff cover,Rola safari rack,Cobra 29 peaked & tuned.

Pastafari Alum, Pink shovel recipient

Update

Some basic troubleshooting of my radiator's electric fan revealed that besides a blown fuse one of the speeds was missing. So I pulled off the electric fan assembly and opened the motor up and cleaned it out. I took lots of pics and plan to post them in the How To section. It really wasn't that difficult.

Then I put it all back together and replaced the blown fuse. A quick run in the woods in 4WD verified the operation of the electric fan but I could smell a strong burnt smell under the hood. I guess the fan motor is toast. I pulled the fuse out before it blew.

I've shopped about and found a brand new one will cost me $340 and a used one $180. Until I can find one I can afford I've modified the wiring and swapped the wiring at the fan. Another run in the woods verified the fan operation without any burnt smell.


By the way, I've given it some thought as to how the PCM selects fan speed. I suspect that if the engine coolant temp begins to climb and you're driving slow the PCM selects the high fan speed and if you're moving fast the slow speed.

_________________
my trail & highway ride (and occasional tow rig)
04 Liberty Sport with a 2.5" lift, ProComp 245/75R16 AT's and two Hella700FF lamps (more accessories to come)

my trail queen
95 YJ with a RE 4" lift, 33" ProComp Extreme's, M8000 Winch, Lockrite Locker up front, Super35 in the rear and 4.88 gears