Hi, 07 DGC with no ac. A few weeks ago I put in a can of 134a with sealer, and a can of 134a. I had ac in the rear, and on the passenger side. Now I have no ac again. I have noticed that when I shut the ac switch off, there is a crackling static noise coming from behind the glove box. Any suggestions please?

 

Take it to a reputable AC service facility. You need to put a set of automotive AC gauges on it to determine system performance. You could have a leak, a clogged component, etc. too many variables in play to offer any sort of accurate advice.

 

Dealership replaced rear evap and lines after dye test. AC is working again.