Intermittent AC and flashing dash light.

[Lord Umoja]

I've tried searching but I can't really find anything that seems like my situation.

I just got my 240 back on the road after 4 years of being parked. The last time I had the car on the road it was converted to R134a coolant and the AC worked fine. As of yesterday the AC did not blow cold. I did the do-it-yourself recharge yesterday and it started working great. Today, not so much.

Before recharge:
AC light on dash stayed on steady
Cool but not cold air from AC
Turning on AC raised idle speed (I left it on because the car stalls at stop lights with the air on but AC off, blaming it on old gas until I run 2 fresh tanks)

After recharge:
AC blows ice cold when I started driving in 80 degree heat
30 min into the drive, AC light begins flashing on/off at roughly a 2 second cycle (1sec on 1sec off)
Flashing light coincides with compressor cycling
AC begins blowing same temp as if AC is off
Compressor drops idle speed instead of raising it (acting like load on engine)
Intermittent belt squeal (changing belts today)

Any help would be appreciated. The convertible is nice but I need AC for super hot days when the top is up and my 11mo old daughter is with me.

[centralcoaster33]

Belt squeal could mean your pulley's aren't rotating properly. The tensioner pulley bearing or the idler pulley bearing on the compressor might be going bad. Maybe run the car with the hood popped and watch your belts and pulleys as the system cycles on and off. See what you can rotate by hand with the belt off.

[Lord Umoja]

Issue was solved. It was related to one hell of a vacuum leak (PCV elbow broke free of valve cover, letting in un-metered air). Now that the leak is fixed, A/C works so good that I don't use it most of the time.