the range should be between the 2 red lines on your dial when you set the bottom blue arrow on the dial to the outside temp on the black ring

 

If that is the reading at startup compressor clutch engaged(should be @ 40psi max) it is definitely overcharged=compressor failure.

 

GM vehicles are very sttrict on how they function. its not like the older early cars. it cannot have air in the lines and it has to have the exact amount of R134 it states under the hood before you can even diagnose an issue. without that you will be chasing your tail till you get fed up and sell the truck

 

Yeah, it's just outside the lines about 54psi low. Earlier today it was 52 PSI 85 deg. and I think it was just within the lines but on high side. But according to chart 85 deg. 45-55 for low is within spec.

 

have you tried recirculating the air to see if the temps get better? sometimes the blend doors do not seat completely because the foam deteriorates on the doors.

 

1 last post, your diy AC PRO is designed to bring more business to the auto repair shops, due to overcharging. Your system is overcharged and I recommend you get to a shop and get an evac and proper amount of recharge before your a/c compressor self destructs, in 3,2,1...

 

i agree with hummerz

 

I've tried and I honestly can't tell that it's doing anything. On last trip out I pushed the recirc button, it stays orange but it didn't get any colder and I checked temp with it on. And right now that button is staying orange but I've had it blink and go out too a few days ago after just pressing it. Yeah, I wonder if it's just a bit overcharged? Is there a way to bleed it off?

I can see/hear the compressor working. And pushing the snowflake button and I can look down at compressor and see it stopped (the front part with ac off) so I know it's engaging. Snow flake on, it's turning fine. Of course it wouldn't get near 53-55 deg out of vents if it wasn't. I have a feeling it's never shutting off since it never cools it enough when set to 60 deg. On a 90 plus day, 53 deg air at vent isn't enough. It takes the edge off, better than nothing but with blower on high going down highway it should freeze you out.

 

back in the day r12 condensors where flushable and had much better flow. like a 3 or 4 row radiator as example but r134 condenser cannot be flushed properly because it is so small and the tubes are minuscule. plus the h2 system is not an independent system like older cars. it is computerized and uses the bcm plus all its sensors to determine when to turn on or off the clutch. the pressure switches and a relay used to do that on r12 system

 

Ok, I think at this point I'll just get it in and have them check it. I've checked everything I could think of and it sounds like it could be a bit over charged then. I'll check it again tomorrow and see where it's sitting. I want to say it was within the red lines earlier but only just.