View Full Version : A/C pulley clutch??

02-17-2005, 04:07 PM
I started up my 99 svt today (just to listen to that sweet sound), and after it warmed up , I noticed a intermittent squeak/chirp kind of sound. I traced it to a pulley on the bottom right of the engine. The culprit pulley according to the underhood diagram is the Air conditioner unit. When I shone a light on it it appeared to have some type clutch set up in the pulley that was intermittently stopping and starting . It would squeak every time it started.
Please excuse my ignorance , but this is all new to me.....Is this normal? How do this assembly work? Any feedback appreciated.

02-17-2005, 04:19 PM
That is your A/C compressor. It has a electric clutch on the pulley that engages when the A/C needs to circulate. When the clutch is off, the pulley spins freely. When the clutch is on, the compressor is circulating the refrigerant through the system. The A/C compressor puts a good amount of load on the engine. It comes on when you run the A/C, max A/C or defrost. Also, Ford has the system setup to where it will automatically cycle the system periodically, even if you do not use it, to keep the system fresh.

If the belt squeaks when the clutch engages (you will see the whole pulley spin instead of just the part with the belt on it), it could either just be an old belt thatís complaining under pressure, or your A/C is freezing up. It all depends on how bad of a squeak you are talking about. If its pretty tame, it could just be the belt. If its loud, it could be the A/C freezing up. If its to a point where it makes you feel uneasy about it, I would suggest getting it checked out, or at least changing the belt if its old (its good practice anyway).

Hope that helps, somewhat. I'm sure someone who can explain it better can clarify this further for you.

02-18-2005, 10:42 AM
Not to say this is any more help. But the clutch inside AC unit could squeak at start up of the AC cycle also.