just noticed, after doing an oil change, and idling the engine hood up, when I turn on my AC, the compressor is constantly cycling on/off... maybe 3-4 seconds on, 2-3 seconds off, repeat. its a warm day outside, maybe 80F, might be 85F in the shade surrounded by sun out on the driveway, but certainly not exceptionally hot. It does seem like my AC isn't cooling quite as well as it used to.

is this normal, or an indication there's something fubar, like high or low freon pressure? fyi, my 1992 740 turbo wagon has a factory R134a conversion, installed by the previous owner.

 

My Jeep would do that when it was low on refrigerant. Charge it up and the cycling would stop.

 

Most likely low on freon. Put a set of gauges on it and go from there.

 

sounds like low refrigerant. Maybe also check for oily residue on AC components to check for the leak?

 

I took it to the shop for an AC service. let them vacuum it down hard, leave it half the day to dehydrate the dessicant and then charge. Seeing as how I'm driving up the central valley next week, where its quite likely 100F +, having functional AC is kind of a priority.