I replaced my viscous fan clutch about 25,000 miles ago with a Borg Warner unit. I was replacing the idler pulleys, bearings, hoses and thermostat so I figured I'd do the clutch while I was at it since it had about 110,000 miles on it and didn't feel all that viscous. Yesterday I left the truck idling for a while with the AC on in 85 degree weather and the temp gauge (my aftermarket one) was up in the 220 range when I jumped back in. It was at 190 while driving. Today, I checked the fan and it spins by hand with very little resistance. What a piece of crap. It was $235 or so for the assembly and I thought Borg Warner made decent products but now I'm not so sure. Has anyone else had a similar experience? I need to get a new one and now I'm not sure which manufacturer to go with. The OEM one seems way too expensive but if it lasts 65,000 miles than it will be a better deal than what I ended up with last time.

 

Did your electric fan come on?

 

It seemed to be on but I wasn't able to confirm that at the time. That may have failed also but the viscous fan is definitely not working. I let the truck idle in my driveway when I got home and it never got over 208 so the electric fan never had a chance to kick on. My temps never went over 195 or so at idle before so something has changed.

 

Did you go through the 'test procedure' for a viscous fan coupling or are you just guessing it's not working when the problem of overheating is really something else.

 

This truck has recent head gaskets, water pump, thermostat, coolant, belt, hoses, and cap. All I did for the viscous clutch was spin it and it turned pretty easily. This morning I checked the electric fan and it was seized. I went to a salvage yard and picked up a fan and clutch from a 2002 D2 and an electric fan that appeared to be brand new for $40 each. They are in the truck now and it idles at 194 with the AC on. I also grabbed the vehicle side of the fan plug which I am going to wire up to some jumpers so that I can fire up the electric fan whenever I change the oil. Clearly not turning on frequently enough leads to it seizing up so I'll make sure it gets to turn once in a while.

 

The efan should run with the AC on. Shouldn't seize up

 

The electric fan only comes on when the coolant gets to 212 degrees or when the AC is on and the ambient temperature is above 82 degrees. The engine never gets above 200 so the fan won't turn on from coolant temp, and here in the northeast the ac on and temp over 82 degrees only happens a few months out of the year so my electric fan doesn't turn for most of the year. I guess an easier and quicker way to get it to spin would be to pull the relay and jump the terminals.

By the way, the truck continues to run nice and cool, and with the engine up to temp, idling in the driveway and the hood open there is a healthy breeze flowing out of the engine bay now. Oh and when you replace a seized fan don't forget to replace the fuse. Seized motor = blown fuse.

 

X2 very commpn problem up here.

 

I would think they would have added a something in the system to kick it on just after starting the engine or something to make sure it would work when needed. I opened mine up and it was seized because rust formed between the armature and the stator. The brushes looked virtually new, the commutator was in perfect condition and the bearings were smooth and shiny. You most likely could take the motor apart, sand off the rust, put it back together and have a perfectly good fan again.