AC pulley sticking...pulley or belt?

[5.0 Nostalgia]

The AC pulley on my dad's 91 GT keeps stopping. My dad noticed it today while he was under the hood. It will stop for a few seconds, then go for a few seconds. I owned the car for for 2 and a half years before he bought it over the summer and never noticed this. Could this be a problem with the pulley? Or maybe the belt?

 

[Mustang5L5]

The pulley or the clutch?

The A/C pulley is two parts, the outer ring freewheels when the A/C is off. WHen the A/C is turned on, the inner part "clutches" the outerring.

WHich part is stopping? the inner clutch or the outer ring?

If the inner part stops and starts with the A/C or defrost on, then the A/C is cylcing. You may be low on refrigerant. Turn the A/C to MAX A/C and watch it. It should remain on continously. I beleive when you put the selector in DEFROST, it will cycle normally. That's why you need to check in MAX A/C

 

[HO93LX302]

Exactally like he said.. The a/c clutch will cycle on and off more frequent when freeon is low... You probably have a leak is the system.. Just as a suggestion.. If your dad wants to keep the a/c in the car and refill it R12 is'nt all that cheap now a days.. Its liquid gold, so if you wanted to you can convert the system over to R134 at a Ford dealer.. The dealer I work for sells a kit that has all new o-rings and a few other things for like $70 or something.. R134 is really cheap, only difference is that it doesn't get as cold as R12.. i have seen it get to around 35 degrees and R12 down to mid 20's.. Just some added advice

 

[5.0 Nostalgia]

I think it is the outer pulley because the AC was not operating when this was happening. It also didn't sound right to me. The pulley that the belt is attached to was the one stopping. I don't think that is supposed to happen because it is probably going to waste the whole belt.