Tempermental AC

[Paul Clark]

Sometimes it works fine for awhile, then stops. It still blows from the dash vents, but it's not AC.
Then kicks in again. This doesn't matter whether or not you've had a load on the engine or any boost.
Sometimes it doesn't kick in until I turn it off and on it a few times.
When it works, it's great. When it doesn't, it's hot.
Any ideas?

 

[Sal Lubrano]

When it stops getting cold does the compressor cluch disengage? If it does a set of gauges will be very helpful but most likely it is a low charge or a bad low pressure cycle switch( the one on the acculmator)I am willing to bet on a low charge. Is the larger line running along top of the radiator getting cold? See if you can get some pressures? Has anyone charged it lately? Could also be overcharged and it is shutting down on high discharge pressure? Is the Electric radiator fan on if it is a GN