Compressor clutch engages, hot air

Tiny
VCHAPMAN
  • MEMBER
  • 2006 GMC SIERRA
  • 6.6L
  • V8
  • 4WD
  • AUTOMATIC
  • 250,000 MILES
With the clutch engaged, outside air temperature blows out the vents. Gauge shows correct pressure when compressor is turned off. South compressor on, pressures drop to zero. Freon tube to dryer ices up.
Do you
have the same problem?
Yes
No
Monday, July 1st, 2019 AT 9:15 PM

4 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome to 2CarPros.

When you say it drops to 0, are you referring to the high side or low side pressure? Can you tell me what the static pressure is on both sides along with outside temperatures when you check?

Here is a link that explains how to vacuum and recharge the system. I'm including it because it shows AC manifold gauges being used. I need to know the pressures on both sides.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

I have to be honest, if the static pressure is correct but everything drops to 0 when engaged, it almost sounds like it's very low on Freon. However, the fact that the compressor engages tells me differently.

Let me know,

Joe
Was this
answer
helpful?
Yes
No
Tuesday, July 2nd, 2019 AT 7:56 PM
Tiny
VCHAPMAN
  • MEMBER
Ambient temps between 85-90 degrees. I don t have gauges for the high side. Only the cheap one on the recharge kit for the low side. Low side was about 45psi static. I am also perplexed that the psi is good static (low side) then drops when clutch engages. Without the Freon can attached, Freon is able to escape when the recharge gauge/kit valve is opened however, when the compressor is engaged, no Freon escapes from the low pressure connection when the same kit valve is opened, which would coincide with a virtually zero reading while clutch is engaged. It makes me think something is clogged or the compressor isn t circulating the Freon? There is a thin coating of ice/frost on the tube near the dryer (I think that s the tubular canister wrapped with insulation near the firewall). The other tube/hoses that are usually cold, aren t but the ones that are usually hot, are hot.

History. I bought the truck 6 mo ago and the air blows super cold but when the fan slows to maintain temp, it won t speed up when the fan is turned up. I can hear the fan blowing but nothing comes out. The previous mention tubes at the dryer has thick amount of ice on it. Once the compressor is turned off, it will continue to blow real cold air until the ice melts and the fan slowly returns to high speed and the air returns to ambient.

I also have a low coolant light that only sets upon start. I have replaced both the reservoir tank as well as the connector. I also replaced the automatic control switches when I bought it due to partial display of numbers. The reservoir always had fluid. Low coolant light still comes on.

I m wondering if the system needs to be evacuated and recharged? Is there an orifice that could be clogged? The compressor appears to be working enough to form ice.
Was this
answer
helpful?
Yes
No
Tuesday, July 2nd, 2019 AT 10:33 PM
Tiny
VCHAPMAN
  • MEMBER
Update: sometimes in life you start to solve a problem assuming you are starting at ground zero only to find out that things are not they way you assumed. I gave up on this A/C and took it to a shop. Ready for this? The previous owner or his mechanic switched the low coolant plug with the low pressure switch plug! I thought I would save you the brain damage that I m experiencing. Thank you for your response and efforts. Sorry I wasted your time but I ll put this one in the memory books!
Was this
answer
helpful?
Yes
No
Wednesday, July 3rd, 2019 AT 3:30 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:

That is a new one for me. LOL Regardless, I'm glad you got it fixed, and you aren't wasting my time. Hope to see you again in the future.

Take care,
Joe
Was this
answer
helpful?
Yes
No
Wednesday, July 3rd, 2019 AT 5:40 PM

Please login or register to post a reply.

Sponsored links