2005 Suburban A/C issue

[utf1234]

My 2005 Suburban has front and rear air. Freon level is good. Blows cold air in both units but while driving it will suddenly start blowing warm air in both units. I can pull over turn the engine off and restart and both units will start blowing cold air again in both units.

Any ideas of where I should start to diagnose the issue?

 

[Donal]

The reset procedure is posted here, probably in the technical section.

 

[Scottydoggs]

my driver side front and rear blend door actuators both took a crap on me. the rear would change hot to cold on its own, same with the front driver side, some times a restart of the engine would fix it, i ended up changing both out. rock auto sells them actuators for like 12 bucks.

the blend door reset didn't change a thing.

 

[utf1234]

It doesn't start blowing hot air like it would if the actuators switched over to heat. It's more like something shuts the compressor off and it takes a restart to get it to work again.

 

[Chevymec]

Have you scanned it for codes? How do you know Freon charge is good?

 

[SnowDrifter]

It doesn't start blowing hot air like it would if the actuators switched over to heat. It's more like something shuts the compressor off and it takes a restart to get it to work again.

Can be difficult to describe, eh? Hot air as in no ac != hot air as in heat

When it acts up, pop the hood and see if the compressor is engaged - it has a clutch. If it's on, you'll see the front of it spinning. If not, then it'll just sort of freewheel like a bicycle. Belt is moving, but the rest of it isn't spinning.

Also ensure that the efans turn on while the compressor is engaged. IIRC the fans are activated via the high pressure switch.

When you say refrigerant levels are good, what are your numbers?