TonyB

So, I've got 1200 miles on the truck and have noticed the fan clutch engaging and disengaging at idle, whether sitting in traffic or sitting in the driveway. It seems to cycle ~15 seconds on & 30 seconds off. It also seems to cycle with the AC clutch. But it does not cycle all the time. This last week, we've had higher temps (75-85) and I'm hearing it more frequently.

Upon initial investigation it appears this is a fluid clutch; is this correct? Or is this an electromagnetic clutch?

Is this operation normal?

TIA

Tony

J BODY

It's a viscous type fan, but has a valve that is controlled by the ECM on it along with a fan speed sensor. ECM can duty cycle the valve and lock the fan up as needed. This will help with maintaining engine temp with better efficiency, and will aid in cooling the a/c condensor so the a/c will perform better at low speeds and idle than the old trucks.

TonyB

J BODY,
Thanks! That explains a LOT!

Has DC released the manuals for '06?

Tony

97Dually

I just found this post and was interested in a manual switch. I have the auto and tow a boat and find in traffic or while manuvering at home my temps go thru the roof!!

I'm thinking a manual switch to enable the fan, regardless of fuel economy loss, this would be a great mod...

Any ideas?