2004 6.0 NV4500 Tahoe

[Dantheman1540]

I’m about to replace all my ac components minus the lines. I bought a good seal/o ring set. My system lost all its refrigerant and the compressor is clanking when I try to spin it. Wish me luck.

New compressor for mine should be delivered today, also doing some ac work this weekend

Hope y’all have better luck than me, despite it holding pressure, being filled to the recommended capacity, and both fans working. The stupid high pressure sensor is staying on making it force the compressor off. I can sometimes override this with HPT, but just today that has only been 50% effective. I’m seriously lost on wtf is wrong.

Obviously it leaked out all its refrigerant sometime last week. Now that it’s been vacuumed and refilled why would it not work as it did just before the system leaked out?

I thought maybe the condenser was getting hot from idling stationary in 100* heat. So I hosed it down until ECT was down in the 140*s and the condenser was cool to the touch. Clearly it’s not a physical issue it must somehow be electrical. Or maybe there’s something in the rear AC system that is ******* up the entire thing, I’ve never touched the system in the trunk.

 

[randeez]

You sure the sensor isn't just bad? I had one that would sit at 100psi with it out of the tube. In the tube it just had a 100psi offset.

Unscrew it from the pipe, leave it plugged in and see what it reads. Gmt900s have a Schrader valve so you can remove it and not lose refrigerant, not sure 800s are the same

 

[Rocket Man]

Dan, sorry I am no help since I know nothing about ac.

Do you guys cap off lines when you disconnect them like all the instructions say? I’m wondering what to use. Everything I’ve read on alldata and the instructions that came with the compressor say to remove the old seals and immediately cap off the lines to prevent contamination and moisture but nothing about what to use.

Edit: I just thought about a piece of plastic wrap and a rubber band….

 

[Tonyrodz]

Dan, sorry I am no help since I know nothing about ac.

Do you guys cap off lines when you disconnect them like all the instructions say? I’m wondering what to use. Everything I’ve read on alldata and the instructions that came with the compressor say to remove the old seals and immediately cap off the lines to prevent contamination and moisture but nothing about what to use.

Edit: I just thought about a piece of plastic wrap and a rubber band….

That should work fine.

 

[Dantheman1540]

You sure the sensor isn't just bad? I had one that would sit at 100psi with it out of the tube. In the tube it just had a 100psi offset.

Unscrew it from the pipe, leave it plugged in and see what it reads. Gmt900s have a Schrader valve so you can remove it and not lose refrigerant, not sure 800s are the same

I swear that I never saw the actual pressure indication channel before, but I found it this time! Looks like it’s reading between 0.0 and 0.02v no matter what I do. The connector is getting a solid 3v so the control is working. Picking up both new sensors now. If that’s not it then it must be a wire problem on the return

 

[Dantheman1540]

I think the compressor is ****** for some reason. I replaced the sensors and it’s reading a little more (up to .18v while on), however the high side pressure just isn’t much even when the compressor commanded on. I though I’d do a test and command the compressor in but turn the fans off to see if the high side rises with the condenser heating up. About 15seconds into this test something started making terrible noises and smoking. Pretty sure it’s the compressor and it’s ****** and so is all the other parts I’ve replaced in the last year. Phuck my life

 

[Dantheman1540]

Turned it back on and commanded compressor to come on hoping I could get a video of the noise and smoke I saw previously. Everything worked fine and the air blew cold no noise, I compared the feel of the compressor clutch to my RCSB and they feel the same. Is there any test I can do to figure out if something internally is causing the compressor to send a signal to the ecu telling it that the pressures are off and it can’t turn on?

If the compressor was totally destroyed it wouldn’t turn back on and idle for 10 minutes with cold air right?

Or am I totally losing my mind? Remember this whole thing started with a leak, I don’t understand how it could so quickly escalate to this.

 

[pwtr02ss]

Turned it back on and commanded compressor to come on hoping I could get a video of the noise and smoke I saw previously. Everything worked fine and the air blew cold no noise, I compared the feel of the compressor clutch to my RCSB and they feel the same. Is there any test I can do to figure out if something internally is causing the compressor to send a signal to the ecu telling it that the pressures are off and it can’t turn on?

If the compressor was totally destroyed it wouldn’t turn back on and idle for 10 minutes with cold air right?

Or am I totally losing my mind? Remember this whole thing started with a leak, I don’t understand how it could so quickly escalate to this.

I'm no pro in the ac department so I'm not much help.

I've had two components cause pressure problems for me. Clogged orifice tube and a dryer that had some moisture and would freeze.

 

[randeez]

i think i need to follow @Rocket Man 's lead and flush everything out on mine, taking a lot of pressure to get it to cool. probably should have anyway since everything is pretty much new except for the evaporator in the dash at this point

 

[Dantheman1540]

What’s so frustrating is mine blows ice cold when the compressor is on and the pressures are in the normal range.

I do notice it seems that when I command the compressor on its causing an abnormal load on he engine. Maybe the compressor is toast yet works fine