Do your fan clutch kick in right when you turn A/C on? Mine goes without for over a minute then kicks in.. sometimes. What regulates the fan when the a/c is on, engine temp or high and low sides pressures?

Thanks

 

Engine temps and pressure. You can cover the condensor with a towel and make the fan engage.....the ecm senses the temp and pressure rise and kicks the fan on to keep everything regulated.....to an extent. If your fan comes on and sounds like a dang tornado I'd say you're probably ok.

 

Trans makes a big difference as well, mine takes a while to kick in with my manual, but the auto's I have messed with kick in almost instantly.

 

What's the scoop on electric fans? Is it worth the effort and money to pull the OE fan and shroud and replace them? At first blush, it would seem that you should see a MPG increase without the "mix-master" churning up front! In Winter the engine has to heat up quicker too.

 

They aren't rated for max GCWR, and most say the see no mileage/power increase from them. Keep the stocker.

 

There is currently no electric fan setup available that comes close to the CFM the stock fan provides. A few people have added an electric pusher fan up front that is triggered by the AC compressor clutch to help out. It's supposed to help with the pressure spikes and really improve AC operation.

I've got a fan ready to put on mine but haven't got around to it yet.

 

there is a TSB on the fan roar

 

Would like to know more about this tsb. Do you have a link to it?

 

TSB # 18-033-07 Rev A

 

It only works on engine temp via the sensor in the fan clutch from what I can remember. It does not work on high side A/C pressure. That's why I have an electric pusher fan on the front of my condensor. I have watched the A/C gauges to many times. In very hot humid weather and the first crank of the day the high side pressures will jump to 450psi easy, hence why most folks can't keep freon in the darn thing.

 

TSB # 18-033-07 Rev A

This TSB is for the early 6.7l and does not look like it has anything to do with fan roaring.