73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: boulky12 on July 10, 2016, 07:26:19 pm
-
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
-
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.
-
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
(http://i1374.photobucket.com/albums/ag415/boulky12/57225_zpsrq534qmz.jpg) (http://s1374.photobucket.com/user/boulky12/media/57225_zpsrq534qmz.jpg.html)
My truck is an 86 GMC Sierra Classic with the Original 305. A/C has been converted to R134.
-
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?
-
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.
-
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?
-
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.
-
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?
-
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.
-
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.
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0480_zpsjdokujmp.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0480_zpsjdokujmp.jpg.html)
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0482_zpslapro9tx.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0482_zpslapro9tx.jpg.html)
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0483_zpsocxikfsm.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0483_zpsocxikfsm.jpg.html)
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0481_zps3wpl41pj.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0481_zps3wpl41pj.jpg.html)
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.
-
What is the idle RPM in drive with the AC off? Post a pic of the accumulator and low pressure cycling switch.
-
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?
-
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.
-
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
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0484_zpsxxjhczqd.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0484_zpsxxjhczqd.jpg.html)
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0487_zpsfslyx1h2.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0487_zpsfslyx1h2.jpg.html)
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0485_zpsuvvdhqmg.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0485_zpsuvvdhqmg.jpg.html)
Thank you guys so much for the help
-
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.
-
Install an idle stop solenoid (https://www.napaonline.com/napa/en/p/CRB22081/CRB22081_0232548168) and tie it into the light green wire that connects to the AC low pressure cycling switch on the accumulator. Look around the driver side of the carburetor for a light green wire in a single wire connector that may already exist for that purpose. The solenoid will energize with the AC and raise the idle speed, so the engine won't stall. Then when the AC is shut off or the engine is shut down the throttle will close to its base adjustment to prevent dieseling.
-
Install an idle stop solenoid (https://www.napaonline.com/napa/en/p/CRB22081/CRB22081_0232548168) and tie it into the light green wire that connects to the AC low pressure cycling switch on the accumulator. Look around the driver side of the carburetor for a light green wire in a single wire connector that may already exist for that purpose. The solenoid will energize with the AC and raise the idle speed, so the engine won't stall. Then when the AC is shut off or the engine is shut down the throttle will close to its base adjustment to prevent dieseling.
Perfect solution.
-
Install an idle stop solenoid (https://www.napaonline.com/napa/en/p/CRB22081/CRB22081_0232548168) and tie it into the light green wire that connects to the AC low pressure cycling switch on the accumulator. Look around the driver side of the carburetor for a light green wire in a single wire connector that may already exist for that purpose. The solenoid will energize with the AC and raise the idle speed, so the engine won't stall. Then when the AC is shut off or the engine is shut down the throttle will close to its base adjustment to prevent dieseling.
Cool I always wondered what that wire and connector were for. So I can just bolt on the Idle stop solenoid and plug in the connector and I should be good to go huh?
Is there an adjustment on the solenoid or do you just put it on?
(http://i1374.photobucket.com/albums/ag415/boulky12/IMAG0488_zpswhcgr1ik.jpg) (http://s1374.photobucket.com/user/boulky12/media/IMAG0488_zpswhcgr1ik.jpg.html)
-
Clean that wire with some solvent and verify the color. Idle solenoid circuits were light green. You can determine whether it is tied into the AC cycling switch using a test light. Connect your test light to a good clean ground and probe the wire connector to determine if it has power only when the AC and/or Defrost are selected from the dash control. Typically, idle speed adjustment with the AC on is 50 - 150 RPM higher than idle speed with the AC off. You can research the idle adjustment specs in the appropriate service manual for an exact RPM setting.
-
Clean that wire with some solvent and verify the color. Idle solenoid circuits were light green. You can determine whether it is tied into the AC cycling switch using a test light. Connect your test light to a good clean ground and probe the wire connector to determine if it has power only when the AC and/or Defrost are selected from the dash control. Typically, idle speed adjustment with the AC on is 50 - 150 RPM higher than idle speed with the AC off. You can research the idle adjustment specs in the appropriate service manual for an exact RPM setting.
Alright thanks and its the light green one for sure its just dirty and hard to see in the pic.
-
Well great news guys I took off the Idle stop solenoid off another truck, slapped it on mine, and now it dosen't die in gear with the A/C on.
I drove my old squarebody with Cold A/C blowing in my face for the first time. It was awesome!
I did notice the rpm's are really low though when I made complete stops but it never died. It sounds bada** like it's cammed but I also dont want it to stall out. What would I adjust for that? The Idle speed screw? Or is the Idle stop Solenoid adjustable?
And as for my compressor clutch sticking, I've done the research on replacing just the clutch, you need special tools and the clutch is pretty expensive, so I'm just gonna get a whole new compressor and clutch when I get the chance. For now I'll just keep smackin that clutch hah.
Thank you guys so much for helping me get this far
-
Your A/C compressor problem is simple to fix.
Basically when the clutch coil is energized the pulley becomes a magnet. The magnet pulls the clutch into engagement.
What has happened to your compressor is the clutch has worn to the point that the clutch is too far away for the magnetic field to pull it in. The coil is still strong because it holds the clutch in once engaged.
You may not need any special tools to fix this. Try tapping the center hub of the clutch in with a hammer while tightening the little nut inside the hub. If you can get the air gap down to .020" then your clutch should work fine.
-
Your A/C compressor problem is simple to fix.
Basically when the clutch coil is energized the pulley becomes a magnet. The magnet pulls the clutch into engagement.
What has happened to your compressor is the clutch has worn to the point that the clutch is too far away for the magnetic field to pull it in. The coil is still strong because it holds the clutch in once engaged.
You may not need any special tools to fix this. Try tapping the center hub of the clutch in with a hammer while tightening the little nut inside the hub. If you can get the air gap down to .020" then your clutch should work fine.
Cool. I'll try that out man. Thanks
-
Adjust the solenoid using the hex plunger that pushes against the throttle lever.
Although the air gap on the clutch is crucial to function, make sure there isn't a simple electrical problem due to poor connection(s). Use a meter to measure the voltage at the clutch coil connector. Connect the meter negative probe to a good clean bare ground then probe both wires connecting to the clutch coil, in turn, using the positive probe. The green wire should measure battery voltage (or charging system if the engine is running) and the black wire should measure zero. Post the results.
-
Adjust the solenoid using the hex plunger that pushes against the throttle lever.
Although the air gap on the clutch is crucial to function, make sure there isn't a simple electrical problem due to poor connection(s). Use a meter to measure the voltage at the clutch coil connector. Connect the meter negative probe to a good clean bare ground then probe both wires connecting to the clutch coil, in turn, using the positive probe. The green wire should measure battery voltage (or charging system if the engine is running) and the black wire should measure zero. Post the results.
Alright I was thinking there was a reason that plunger had a hex on it.
And one of the first things I did was clean all connections and ground but I'll go ahead and get those readings just to see.
-
I'm pretty good but Vile and BD can help you much better than I can. I would continue with their suggestions.
-
Alright guys its fixed. My compressor is functioning perfectly now.
I went to orielly's to rent out the A/C clutch tools. When I tried to use them none of them would screw on. I think the threads on the shaft holding the clutch are stripped. So after I couldn't get that to work I decided to try to hammer that sucker in like Engineer said.
I took off my top fan shroud to get more clearance. I was smacking the clutch in with a 4lb mini sledge hammer and a piece of wood in between. And I also used one of those rubber dead blows. I kept track of the gap using a business card. Once I felt good resistance on the card I stopped. I tried to tighten that little nut inside the hub, but it just made the whole compressor spin, so i just left it.
So far so good. I've turned it on and off several times and been driving her and it's working perfectly.
Thank you guys so much for helping me get cold A/C in my truck.
-
Adjust the air gap on the compressor clutch hub.I wouldn't hit it with a hammer
cause you could damage the compressor.Most chain parts store rent the tools to replace
the clutch.It's simple just remove the shaft nut and install tool and push hub on
till you reduce the clearance..020 should be good although it may be hard to measure
due to wear.You can either re-install the nut or leave it off.Most new compressors
of that style won't have one