2006 Ford 500, has a new a/c system, wont blow cold air. Took it to the shop, they replaced compressor and dryer under warranty. Still wont blow cold air, so they replaced the freeze lines, still no cold air. They dont know what is causing it. Anyone had this issue before/have an idea as to the cause?

Have they checked the orifice/expansion valve?

I fixed a friends 07 ford 500 recently and it was the scroll valve in the compressor. Since you replaced the compressor, you also replaced this valve. Start with hooking up manifold gauges and base your diagnosis on low and high side pressures. Cold be an expansion valve stuck closed or a clog in the system. A pressure reading would determine this.

Is compressor coming on? Relay or pressure switch bad?

First, I would look/see if the compressor is even kicking on. Did they forget to evacuate and recharge the system with about 28 ounces of 134a refrigerant? Sounds like they need to start with a correct diagnosis before throwing any more parts at it. Good luck with these guys.

hate to ask....is the a/c clutch working??

Have they checked the computer on the car or even the controls internally that turn on the AC. Could be something in the dash that is not connecting. Check all the fuses and even the relays on the fuse panels.