AC clutch engages and then stops, engages and then stops
#1
AC clutch engages and then stops, engages and then stops
90 RS 305 tbi, mostly stock.
The AC hasn't worked for years, and I finally got around to looking at it today. When I turn it on, the clutch for the compressor will engage and the pulley for the compressor will spin--but then after 4-5 seconds, it stops and the belt just spins around as if the AC were off. Then after 4-5 seconds of being off, it will engage the clutch again, for 4-5 seconds. Then off, then on, then off, then on in a very set rhythm.
So basically the clutch engages, but then something stops it from continuing to engage, and then it keeps trying over and over again to start up again but something keeps stopping it.
Is this an easy fix? Does it simply need a recharge? I don't see any stickers anywhere indicating a conversion to 134a, all stickers point to R12 so it no doubt has been a long, long time. Then again, I always learned that if it needs a recharge, it's got a leak somewhere and a part that probably needs to be replaced.
The AC hasn't worked for years, and I finally got around to looking at it today. When I turn it on, the clutch for the compressor will engage and the pulley for the compressor will spin--but then after 4-5 seconds, it stops and the belt just spins around as if the AC were off. Then after 4-5 seconds of being off, it will engage the clutch again, for 4-5 seconds. Then off, then on, then off, then on in a very set rhythm.
So basically the clutch engages, but then something stops it from continuing to engage, and then it keeps trying over and over again to start up again but something keeps stopping it.
Is this an easy fix? Does it simply need a recharge? I don't see any stickers anywhere indicating a conversion to 134a, all stickers point to R12 so it no doubt has been a long, long time. Then again, I always learned that if it needs a recharge, it's got a leak somewhere and a part that probably needs to be replaced.
#2
Supreme Member
![](https://www.thirdgen.org/forums/images/ranks/tgo10.gif)
Join Date: Sep 2002
Location: Cary, North Carolina
Posts: 9,192
Likes: 0
Received 16 Likes
on
16 Posts
Car: 1992 RS
Engine: Carbed 350
Transmission: 700R4
Axle/Gears: 3.42 posi
Re: AC clutch engages and then stops, engages and then stops
It will normally cycle on & off - but cycles at a faster rate if it's low on freon - and I'm not sure it will cycle at all if the freon is too low, but I'm no expert on A/C. But I do know that cycling on/off is normal.
#3
Re: AC clutch engages and then stops, engages and then stops
Yeah that's what I know too, it just seems odd that it cycles on and off so fast and so rhythmically. I don't remember the AC ever flat out breaking, going from working one day to not working the next, so maybe it is just out of freon
#4
Senior Member
![](https://www.thirdgen.org/forums/images/ranks/tgo10.gif)
Re: AC clutch engages and then stops, engages and then stops
It will cycle faster and faster like that until freon gets so low that it won't build enough pressure to activate it. Sounds like it needs a freon charge and maybe a leak check.
Thread
Thread Starter
Forum
Replies
Last Post
Drone358
Transmissions and Drivetrain
4
12-10-2015 08:16 PM
Night rider327
Engine/Drivetrain/Suspension Parts for Sale
0
09-02-2015 04:17 AM