A/C Compressor Clutch?

B_Faja · July 9, 2019

Desperate for help! Long-time lurker...

I have a '15 Sierra 5.3L with some A/C problems and I can't take the heat! Last summer it wouldn't hold any refrigerant and I didn't fix it right away because I would be gone overseas for 9 months. When I got back, I replaced the infamous condenser that displayed huge amounts of leakage in the same upper right corner. Pulled a vacuum, charged it, PAG oil, etc... it worked perfectly for about 5 months. NOW.... out of nowhere, it's blowing hot air again. I hooked up gauges and initially before doing anything else it showed 100PSI on the low and 150PSI on the high with the compressor refusing to engage. I've replaced the pressure sensor hoping for a cheap fix to no success. Pulled a vacuum (vacuum held for 15 minutes) and attempted to refill, but the compressor refuses to engage. Upon starting the engine the clutch face looks like it is engaging and stops after a few seconds. With the A/C on, the clutch face IS magnetized and seems like it is attempting to engage spinning slowly and making half turns every so often. It doesn't make any weird noises and is free spinning while "engaged". I have read about trying to jump the clutch coil directly with battery power to see if it engages, but I don't know if there is an easier way (i.e. relay) than reaching down to the harness on the compressor.

Do I need a new compressor? Or a new clutch? Or can someone smarter than me tell me what I'm doing wrong haha

Edited July 9, 2019 by B_Faja

Salciido_z71 · August 15, 2019

I see you have no reply’s, but did you ever figure this out? Mine went out today and I’ve been doing research on this all day and tbh I never knew about the condenser problems GM has with all these trucks. I read somewhere that Yukon, Tahoe, and Escalade got there warranties extended and even though Silverados and Sierras use the same setup they got denied, but anyway the belt on mine snapped at first I thought the truck was catching on fire due to some light bars I had installed a few weeks ago good thing was I was barely pulling out of my drive way when I saw a bit of smoke coming from under the hood (light bars are installed inside grille) well turns out I heard a sizzling noise and when I looked down I saw the belt snap off I noticed that the crank pulley and compressors pulley had rubber within the grooves but it didn’t make sense to me then. My truck is a 15 74k now so I thought normal wear and tear since the belts it had on were still the original that came on the truck when I bought it new. So I bought all 3 belts put them on and fired her up well I saw the clutch wanting to engage and stop and then again making an attempt as I signaled my buddy to shut it off, well it snapped the new belt too. So this was all new to me and started doing research after reading and looking around I checked to see if the compressor was the issue or the clutch well turned out it’s the clutch it seized up. I was thinking about just replacing the compressor and I also called the dealership. I rather replace it myself the whole assembly, might as well since I’m removing the compressor. I will be replacing the condenser, compressor, engagement valve, o-rings, receiver etc.. all that for $340 shipped they are GPD brand( brand is supplying warranty customers from what I’ve read) then my mechanic will handle the rest. By the time it’s fixed I will have paid $500 so hope all goes well. The dealer wanted $1200. Hopefully yours has been fixed, and I just thought I’d share this with someone since I have never typed anything on here lol so I’m kinda venting in a way at the same time. ✌

Edited August 15, 2019 by Salciido_z71
Typo

jay webb · August 17, 2019

On 7/8/2019 at 9:07 PM, B_Faja said:

Desperate for help! Long-time lurker...

I have a '15 Sierra 5.3L with some A/C problems and I can't take the heat! Last summer it wouldn't hold any refrigerant and I didn't fix it right away because I would be gone overseas for 9 months. When I got back, I replaced the infamous condenser that displayed huge amounts of leakage in the same upper right corner. Pulled a vacuum, charged it, PAG oil, etc... it worked perfectly for about 5 months. NOW.... out of nowhere, it's blowing hot air again. I hooked up gauges and initially before doing anything else it showed 100PSI on the low and 150PSI on the high with the compressor refusing to engage. I've replaced the pressure sensor hoping for a cheap fix to no success. Pulled a vacuum (vacuum held for 15 minutes) and attempted to refill, but the compressor refuses to engage. Upon starting the engine the clutch face looks like it is engaging and stops after a few seconds. With the A/C on, the clutch face IS magnetized and seems like it is attempting to engage spinning slowly and making half turns every so often. It doesn't make any weird noises and is free spinning while "engaged". I have read about trying to jump the clutch coil directly with battery power to see if it engages, but I don't know if there is an easier way (i.e. relay) than reaching down to the harness on the compressor.

Do I need a new compressor? Or a new clutch? Or can someone smarter than me tell me what I'm doing wrong haha

ok just cuz you have pressure readings on the gauges dont mean its has the correct amount of charge. i would evac the system , check the charge level, if it is fine then most likely its a faulty compressor. the pressure of the refrigerant is related to temp. say at 80 degrees low humidity it should be like 30-40ish low side, 125-145ish high side while running with ac on. ( this is just an average for example) you can look and see if the compressor is actually engaging. also these have a separate ac belt. make sure that didnt break , it typically does if the compressor locks up. now if you dont have a leak and you have the truck running/ac on max recirculate. and you have wacked pressure its most likely a faulty compressor.

B_Faja · August 20, 2019

On ‎8‎/‎15‎/‎2019 at 3:37 AM, Salciido_z71 said:

I see you have no reply’s, but did you ever figure this out? Mine went out today and I’ve been doing research on this all day and tbh I never knew about the condenser problems GM has with all these trucks. I read somewhere that Yukon, Tahoe, and Escalade got there warranties extended and even though Silverados and Sierras use the same setup they got denied, but anyway the belt on mine snapped at first I thought the truck was catching on fire due to some light bars I had installed a few weeks ago good thing was I was barely pulling out of my drive way when I saw a bit of smoke coming from under the hood (light bars are installed inside grille) well turns out I heard a sizzling noise and when I looked down I saw the belt snap off I noticed that the crank pulley and compressors pulley had rubber within the grooves but it didn’t make sense to me then. My truck is a 15 74k now so I thought normal wear and tear since the belts it had on were still the original that came on the truck when I bought it new. So I bought all 3 belts put them on and fired her up well I saw the clutch wanting to engage and stop and then again making an attempt as I signaled my buddy to shut it off, well it snapped the new belt too. So this was all new to me and started doing research after reading and looking around I checked to see if the compressor was the issue or the clutch well turned out it’s the clutch it seized up. I was thinking about just replacing the compressor and I also called the dealership. I rather replace it myself the whole assembly, might as well since I’m removing the compressor. I will be replacing the condenser, compressor, engagement valve, o-rings, receiver etc.. all that for $340 shipped they are GPD brand( brand is supplying warranty customers from what I’ve read) then my mechanic will handle the rest. By the time it’s fixed I will have paid $500 so hope all goes well. The dealer wanted $1200. Hopefully yours has been fixed, and I just thought I’d share this with someone since I have never typed anything on here lol so I’m kinda venting in a way at the same time. ✌

Hey! I ended up just replacing the entire compressor. I still don't know why it was doing that, but didn't want to mess with taking it apart and putting a new clutch assembly on.

$340 is an awesome deal though! and yes, shops around here wanted about the same ($1200-1800) to fix it.... Hopefully yours is fixed! Too hot out here.

B_Faja · August 20, 2019

On ‎8‎/‎16‎/‎2019 at 11:16 PM, jay webb said:

ok just cuz you have pressure readings on the gauges dont mean its has the correct amount of charge. i would evac the system , check the charge level, if it is fine then most likely its a faulty compressor. the pressure of the refrigerant is related to temp. say at 80 degrees low humidity it should be like 30-40ish low side, 125-145ish high side while running with ac on. ( this is just an average for example) you can look and see if the compressor is actually engaging. also these have a separate ac belt. make sure that didnt break , it typically does if the compressor locks up. now if you dont have a leak and you have the truck running/ac on max recirculate. and you have wacked pressure its most likely a faulty compressor.

the pressure reading I posted were static readings without the compressor engaged, and if it was engaged, it would still be way off. The issue was that the compressor wouldn't engage.... so I couldn't charge it (correctly by weight, not a pressure range). Belt was good. You could see it trying to engage and you could feel when it was magnetized, it just wouldn't catch completely and only make half spins before stopping. I assume the gap adjustment was off or the clutch was just bad... either way, replaced the whole compressor and its all good.