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AC compressor clutch problems

T

TomsToy

Guest
Was driving saturday and saw a puff of smoke comming out of the front. Stopped and discovered an ooze of what appeared to be burned plastic comming out from around the AC clutch. Smelled like electrical insulation burning. You can still turn the compressor freely, so I know it's not frozen. You think the clutch just torched itself or did the compressor cause the clutch to buy the farm? Should I change both?
Is this common in C4's?
Tom
 
T

Tonylong

Guest
I had a similar thing happen last July on my '89.
I was running with the top down and the AC on full for all those hot
days, then suddenly gobs of white smoke from under the hood.
When I got home several minutes later I found the serpentine belt was
what was smoking. Either the compressor or clutch was shot.
Disconnecting the clutch lets me run the car. I replaced the belt, but still have
no working AC. Don't know if it's the clutch or the compressor yet.
Costs $1,000 plus to fix it. Maybe some time later.
How is your belt ?
 
T

TomsToy

Guest
Thanks Tony

Yep, don't that toast ya when they say $1,000 and break out into a smile. Don't mind a fellow makin a buck but that's a hard one to swallow.
Tom
 
T

TomsToy

Guest
belt

Belt's in good shape. No sign of lockup burns. I'm still wondering what caused it. Sure runed my fun in the sun, anyway.
T
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
/TOM ... Stopped and discovered an ooze of what appeared to be burned plastic comming out from around the AC clutch. Smelled like electrical insulation burning. You can still turn the compressor freely, so I know it's not frozen.
Probably the clutch's solenoid windings/terminals shorted. Probably just replace the clutch ... first check wiring from clutch for shorts-opens-grounds.
JACK:gap
 
T

TomsToy

Guest
shorts

I'll check the terminals tonight for shorts. Thanks
 
T

TomsToy

Guest
Pic of the culprit

Here's a pic of the ooze
 

Redbob

Well-known member
Joined
Dec 5, 2001
Messages
239
Location
Cross Roads, Texas, U.S.
Corvette
'89 dk red coupe
"Was driving saturday and saw a puff of smoke comming out of the front. Stopped and discovered an ooze of what appeared to be burned plastic comming out from around the AC clutch. "

I'm very familiar with this problem, having had it happen to my '89 3 times before I finally wised-up. It's just the clutch, and NAPA has one for a pretty reasonable price: if memory serves, it's under $200. I bought a Sears 3/8" butterfly air impact and 10mm impact socket for getting off the center bolt - since with a dead clutch, there's no way to keep the compressor from turning!

The solution, to keep this from happening again, is to have both of your electric fans running at all times when the A/C is on.
I know the computer is supposed to turn on the fan behind the radiator as soon as the A/C is turn on, but that's not good enough, at least not here in North Texas, where an "average" summer day will be 105 degrees at quitting time. How you do this is up to you; I just wired my fan solenoids to toggle switches. You've got to remember to turn them on, though!

What's happening to the clutch is that excessive A/C "head-pressure", the pressure developed by the compressor, is causing the clutch to lock-up. There's just too much torque required to turn the compressor. Headpressure is reduced by improving the airflow over the condenser, the heat exchanger out from t of the radiator.
- R
 
T

TomsToy

Guest
Hot vette

Hey, Thanks RedBob.! I'll try that. I guess I need to change some wiring also.
Thanks
Tom
 
J

jimmijimj

Guest
Thanks a bunch b Redbob------jimmijim

thanks to the internet and you through this forum I am once again well informed to make a decison on what route to follow in having my AC fixed. Found an AC compressor clutch available through Auto Zone for 149.00 plus change Wil be back for tech tips and also to shoot the chitt. jimmijim:happyanim: QUOTE=Redbob;87714]"Was driving saturday and saw a puff of smoke comming out of the front. Stopped and discovered an ooze of what appeared to be burned plastic comming out from around the AC clutch. "

I'm very familiar with this problem, having had it happen to my '89 3 times before I finally wised-up. It's just the clutch, and NAPA has one for a pretty reasonable price: if memory serves, it's under $200. I bought a Sears 3/8" butterfly air impact and 10mm impact socket for getting off the center bolt - since with a dead clutch, there's no way to keep the compressor from turning!

The solution, to keep this from happening again, is to have both of your electric fans running at all times when the A/C is on.
I know the computer is supposed to turn on the fan behind the radiator as soon as the A/C is turn on, but that's not good enough, at least not here in North Texas, where an "average" summer day will be 105 degrees at quitting time. How you do this is up to you; I just wired my fan solenoids to toggle switches. You've got to remember to turn them on, though!

What's happening to the clutch is that excessive A/C "head-pressure", the pressure developed by the compressor, is causing the clutch to lock-up. There's just too much torque required to turn the compressor. Headpressure is reduced by improving the airflow over the condenser, the heat exchanger out from t of the radiator.
- R[/QUOTE]
 

boomdriver

Well-known member
Joined
Dec 18, 2008
Messages
1,888
Location
texas
Corvette
87 z-51
thanks to the internet and you through this forum I am once again well informed to make a decison on what route to follow in having my AC fixed. Found an AC compressor clutch available through Auto Zone for 149.00 plus change Wil be back for tech tips and also to shoot the chitt. jimmijim:happyanim: QUOTE=Redbob;87714]"Was driving saturday and saw a puff of smoke comming out of the front. Stopped and discovered an ooze of what appeared to be burned plastic comming out from around the AC clutch. "

I'm very familiar with this problem, having had it happen to my '89 3 times before I finally wised-up. It's just the clutch, and NAPA has one for a pretty reasonable price: if memory serves, it's under $200. I bought a Sears 3/8" butterfly air impact and 10mm impact socket for getting off the center bolt - since with a dead clutch, there's no way to keep the compressor from turning!

The solution, to keep this from happening again, is to have both of your electric fans running at all times when the A/C is on.
I know the computer is supposed to turn on the fan behind the radiator as soon as the A/C is turn on, but that's not good enough, at least not here in North Texas, where an "average" summer day will be 105 degrees at quitting time. How you do this is up to you; I just wired my fan solenoids to toggle switches. You've got to remember to turn them on, though!

What's happening to the clutch is that excessive A/C "head-pressure", the pressure developed by the compressor, is causing the clutch to lock-up. There's just too much torque required to turn the compressor. Headpressure is reduced by improving the airflow over the condenser, the heat exchanger out from t of the radiator.
- R
[/QUOTE]

Thats not why the clutch fails....ALL a/c systems have challanging head pressures. If your hi-pressure cut out switch is bad then you will run excessive pressures.Dirty clutches with oil cause slipping that will cause the clutch to eventually burn up.
The hi-press cut out is what saves the compressor.Its a safety device for the compressor.
What KILLS compressors and clutches is starting the motor or shutting it off with the a/c left "on". Always turn a/c off before shutting down the engine and only turn a/c on with the engine running at least normal idle.
 

gmjunkie

Well-known member
Joined
Nov 11, 2004
Messages
4,547
Location
Old Fort NC/Vero Beach FL
Corvette
03 Z-51,78 L82 Coupe
Thats not why the clutch fails....ALL a/c systems have challanging head pressures. If your hi-pressure cut out switch is bad then you will run excessive pressures.Dirty clutches with oil cause slipping that will cause the clutch to eventually burn up.
The hi-press cut out is what saves the compressor.Its a safety device for the compressor.


smiley4.gif smiley4.gif smiley4.gif
And you forgot to mention that it helps allot if the clutch is shimmed properly too!~!!:thumb

PS HPS saves allot more than compressors,Might save your eyes someday,Hoses,Condensers,Evaporators,They'll all come apart given enough pressure!~!!
 

ecss

Well-known member
Joined
Nov 27, 2004
Messages
649
Location
Windsor Mill, MD
Corvette
89 Brilliant Red Metallic
What KILLS compressors and clutches is starting the motor or shutting it off with the a/c left "on". Always turn a/c off before shutting down the engine and only turn a/c on with the engine running at least normal idle.

:confused

The AC clutch coil only has 12 volts applied to it when the ignition switch is ON. In START mode there is no 12 volts to the clutch coil.

No need to turn off the AC before shutting off the engine or before
starting it.
 

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