BMW Blog

Hey guys, I just installed a new a/c compressor and dryer and have it vacuumed and ready to charge, but when i turn on the a/c, the compressor does not engage. Ever since i bought the car the a/c has been broken so i don't know where to begin here. All i know is 95 weather is really starting to piss me off. Where should i begin checking? I checked the voltage to the plug at the compressor and there was nothing and there are no blown fuses.... What should i start checking next??

You said "ready to charge". If there is low/no pressure in the system the compresser won't turn on.

how would know if my compresser turns on or not

Until you recharge the system the compressor won't come on. There is a low pressure switch that keeps the compressor from "Running Dry" since the Freon has the lube in it. So put some freon, leak test dye and correct oil into the system. If the system has been open and exposed to air, change the receiver/dryer also.

If the compressor won't turn at all because the system is empty, how do you fill the system without the compressor providing suction. Kinda like the chicken or the egg...any ideas?

ok i got it.. i misunderstood when it said to turn the ac on full blast... I assumed this would mean the compressor is running which it doesnt. As soon as i put half a can of freon in there it kicked in. Yay!

If the compressor won't turn at all because the system is empty, how do you fill the system without the compressor providing suction. Kinda like the chicken or the egg...any ideas?


thats is why you are suppose to flush and then make a vacuum, beside the freon is under pressure