Hi! I've done a lot of research and am unable to figure out my problem. I recently purchased a 2010 Chevy Express 4500 w/ a shuttle bus on back. The ac hasn't worked since I bought it. I thought the rear ac was blowing cold when I tested but not sure and now no cold from either front or back.

The compressor was cycling on and off about every 10 seconds. I jumped the low pressure switch and the clutch released and the compressor was spinning. The gauge was reading under 10 psi. I added a bunch of r134a thinking it was just low. I added around 48 oz and the gauge read 40 psi. Still no cold air. I could feel different lines and coils under the dash and going through the fire wall that are ice cold but no cold air from vents. The blend actuator and door seem to work fine when I change temp.

Any other thoughts?

 

Is it blowing warm air or nothing at all?

 

It seems to have held all the 134 overnight and is still at 40psi today. I do feel some cold air now instead of hot air but very little volume of air coming out.

 

It actually seems like there's a door or flap that's not right. The back ac blows cold now and the front blows cooler but not cold. I'm not sure where all the flaps are or which it would be. I found some under the passenger side dash near the heater core and one of the flaps only closed partially. Not sure how they're supposed to be.

 

I've got the dash all put back together and wanted to update. All the diverters and mixing doors seem to work but it just isn't that cold when the ac is on.

Could this be something unrelated to the doors? Compressor seems fine, 134 levels seem fine, etc. Back ac unit blows cold now but front is just around 60-70 degrees. Cool but not cold.