Lately I’ve been getting a loud squeal at the motor. Only happens when the heater is on. Checked around and it appears to be the AC clutch partially engaging. I’m going to check it with a squirt of water to verify. Question is: why is the AC kicking on when the heater is on at the hottest temperature? Is the clutch energized to disengage and maybe my clutch coil is getting weak?
97 F150 w/4.2L

 

The compressor will run in all positions of the selector except Floor and Vent.

 

You are right. The sound does not come on when the selector switch is in the floor or vent positions. Now why is the AC coming on when the heat adjuster is all the way to heat position? Thanks for your response.

 

For dehumidification purposes. That's how the system works.

 

x2..

It will clear up your foggy windows.

Think of it as an added bonus... a lot of other car/truck manufacturers don't use the A/C unless you actually press the A/C or the Defrost button.

 

I think I'd prefer a button.

 

Then buy a Civic.

 

Its also good for the health of the system for the A/C to be operated regularly. If it doesn't seals start to dry and shrink and then you get all sorts of nice repairs!

 

Isn't that pretty drastic?

 

At least then we won't be listening to him whine about the way Ford decided to do it....

 

I dunno... I don't care if it turns the A/C on or not...

In fact it is good that Ford did it this way, because it puts the compressor to use rather than it sitting idle all winter.

 

What makes you think I'm whining? All I did was express a preference. No vehicle is perfect.

 

Does the clutch get weak over time? What causes the squeal? It's embarrassing at a stop light. What's the fix and how much does it cost and where do you get the parts and do you have to discharge/recharge the system and which one of you are going to come to my house and fix it?