A/C Compressor Clutch Sticking?

[boulky12]

I was messing with my A/C compressor today to see if I could get it to kick on.

I replaced the connector from the harness to the compressor cuz it was toast.

I cleaned and sanded the contacts and ground.

That didn't do it. So I decided to give the clutch a wack with my water bottle and it kicked on and I felt Cold A/C in my truck for the first time!

I turned the A/C off, then back On, and it was stuck again. Wacked it again with the water bottle and it kicked in again.

Is there anything I can mess with that will make the clutch unstick so that i don't have to pop the hood and smack the clutch when i want Cold A/C. Or am i just going to have to buy a new compressor?

I appreciate the help. Thanks

[LTZ C20]

Which compressor do you have? Year, model & engine of the truck? Some compressor clutches can be serviced or replaced on their own without having to replace the entire compressor.

[boulky12]

Which compressor do you have? Year, model & engine of the truck? Some compressor clutches can be serviced or replaced on their own without having to replace the entire compressor.

I have this compressor


My truck is an 86 GMC Sierra Classic with the Original 305. A/C has been converted to R134.

[boulky12]

Oh and another thing. When I put the truck in gear with the clutch engaged, the rpms drop really low and she stalls out. Am I gonna have to mess with the carb for that?

[LTZ C20]

I have the same compressor. The clutch can be serviced separately, good news for you!

As for the idle dropping low, 1: you could have a low curb idle speed setting, the extra load of the ac stalls the engine. 2: the throttle plates and bore are coked up, causing a low idle speed and stall with the ac on. 3: being an 86, that should have the computer controlled Quadrajet, it's possible that the idle speed is not being compensated for the ac on, increasing idle speed to maintain the desired rpm in gear.

[boulky12]

As for the idle dropping low, 1: you could have a low curb idle speed setting, the extra load of the ac stalls the engine. 2: the throttle plates and bore are coked up, causing a low idle speed and stall with the ac on. 3: being an 86, that should have the computer controlled Quadrajet, it's possible that the idle speed is not being compensated for the ac on, increasing idle speed to maintain the desired rpm in gear.

So should I just increase the idle with the Idle speed screw on the driver's side?

And is it possible to increase the rpm in gear but not in park.

I'm sure i could keep her alive by cranking up that Idle speed screw, but then won't I be left with a high idle in park?

[LTZ C20]

The first thing you should do if find out why it's stalling before actually performing a repair. I only mentioned a few of the things it could be but a diagnosis is still needed.

[boulky12]

The first thing you should do if find out why it's stalling before actually performing a repair. I only mentioned a few of the things it could be but a diagnosis is still needed.

Well it only stalls when I have the A/C On and I drop it in gear.

What else can I try to diagnose?

[LTZ C20]

First look in the throttle bore and see if the bore an throttle plates are dirty, black colored. Also, with the truck off, slowly rotate the linkage fully open and back closed with your hand, feeling for any unsmoothness in rotation. This is to check if the throttle parts are dirty and sticking or coked up.

Report back with your findings, also take pics and post them. That helps alot.

[boulky12]

First look in the throttle bore and see if the bore an throttle plates are dirty, black colored. Also, with the truck off, slowly rotate the linkage fully open and back closed with your hand, feeling for any unsmoothness in rotation. This is to check if the throttle parts are dirty and sticking or coked up.

Report back with your findings, also take pics and post them. That helps alot.

Everything inside looks pretty clean. And linkage feels pretty smooth when I rotate it.

I believe the carbs been rebuilt before because the airhorn gasket dosen't look like its 30 years old and the cover for the electric choke coil is held on with screws instead of the factory rivets.

Let me know if I can take anymore pics that will help.

[bd]

What is the idle RPM in drive with the AC off?  Post a pic of the accumulator and low pressure cycling switch.

[Stewart G Griffin]

I have the same compressor. The clutch can be serviced separately, good news for you!

As for the idle dropping low, 1: you could have a low curb idle speed setting, the extra load of the ac stalls the engine. 2: the throttle plates and bore are coked up, causing a low idle speed and stall with the ac on. 3: being an 86, that should have the computer controlled Quadrajet, it's possible that the idle speed is not being compensated for the ac on, increasing idle speed to maintain the desired rpm in gear.

But i thought only california trucks had CCC?

So, in that case (if true) then shouldn't there  an idle stop solenoid thingy that turns on when the A/C is turned on to bump the idle up?

[LTZ C20]

Answer BD's questions also. I'm not sure on whether that was California only or not.  The carb looks good so it's safe to say that's not the issue. As BD said, please answer these:

1) idle speed in PARK with a/c OFF.

2) idle speed in PARK with a/c ON.

3) idle speed in DRIVE with a/c OFF.

4) idle speed in DRIVE with a/c ON just before it stalls.

[boulky12]

What is the idle RPM in drive with the AC off?  Post a pic of the accumulator and low pressure cycling switch.

Truck dosen't have a tach but I have one laying around. I'll hook it up when I get some time and get those readings





Thank you guys so much for the help

[LTZ C20]

Sounds good. It shouldn't be hard to took the tach up. You can even but alligator clips on the power and ground wires, clip them onto the battery and a female spade connector for the tach signal on the distributor.