Weird A/C problem

[Hon2BMW]

Do our cars have a pressure switch on the compressor for the A/C?

Its finally cooled down here in AZ (upper 80's instead of 100+) so I haven't been riding with the A/C on for a week or two. Suffice it to say the A/C was working like a charm before today.

Now when I turn it on, I feel what I believe is the compressor clutch engaging ( I can see/hear the RPMs jump up a bit and hold) but I'm not getting any cold air out of the vents, and the lines in the engine compartment do not get cold.

On my honda, if there was not enough coolant in the system the compressor clutch would not engage due to the pressure switch cutting the circut to protect the compressor from damage.

Since the clutch on the compressor still feels like its engaging I don't know whats going on, I'm going to remove the bumper tomorrow to see if there's a visible hole in Condenser anywhere. I also think I have an old R-134 charge kit in my storage with a pressure gauge, so maybe I'll try to see whats going on in that respect.

But does anyone else know what it might be? Like I said the system was working fine a few weeks ago.

[jlevie]

There are low and high pressure switches in the receiver/dryer. A low or overcharged condition will prevent the clutch from engaging, which is easy to check by looking at the compressor pulley with A/C enabled.