fan clutch operations

[mickalo]

Was planning on changing my belt and idler pulley tomorrow and was checking the fan clutch, with engine cold, it seemed a little stiffer then I would have thought with a cold engine. It turns by hand but I thought it be a bit more "free wheeling" when the engine is cold. Would there be some resistance turning the fan when engine is cold? Also what exactly does the electrical connections to the fan do is this tied into the temp sensor circuit ?

this is for a ford explorer 2010 xlt 4.0L

TIA

 

[dlundblad]

You're feeling the resistance of the oil in the crooks and crannies of the clutch. Technically it's engaged, which is why you hear fans roar on a cold engine. One the engine is on and the clutch spins, the oil is brought to the outside of the clutch. The thermal band hooked up to the valve is what engages and disengages the clutch when the engine is hot.

You could test it by sticking a roll of newspapers slightly into it (with the spin.. not against it) when the engine is hot. If the fan stops turning, you know it works.

I have no idea on your electrical connections. Sorry.

 

[mickalo]

ok thanks for the tip. i haven't any real issues with it was more curious and wasn't real sure what the elec., connections actual does with the fan.

 

[brave sir robin]

The electrical connection is how it locks up. Instead of working directly off of air temperature it gets a signal from the ECU telling it when to lock up. If the engine isn't getting hot and the AC is still blowing cold at idle I would not mess with it.

 

[mickalo]

Originally Posted By: brave sir robin
The electrical connection is how it locks up. Instead of working directly off of air temperature it gets a signal from the ECU telling it when to lock up. If the engine isn't getting hot and the AC is still blowing cold at idle I would not mess with it.


That's what i thought but wasn't 100% sure about that too lazy to dig through my electrical manual covering this explorer appreciate the info. No problems with the fan it's seems to be working fine just was curious about it operation to better understand it or trouble shoot when and if necessary helps to understand what your working on.

 

[berniedd]

My 2009 Ford uses a mechanical fan clutch. A few months ago, the A/C wouldn't cool in traffic but got slightly colder once the car got moving. The shop used dlundblad's newspaper trick while the engine was COLD and the fan would stop. Opened up the fan clutch and the oil was gone. (How would it dry up? It's a closed and sealed chamber!) Replaced the silicone oil and everything's back to normal. Fan now pulls more air at all engine speeds compared to before.