A/C help

[timtiminy]

okay my air conditioning doesnt work. i push the ac button and the light doesnt turn on and it doesnt accuate the compressor clutch. Electrical? where do i start? anyone have this problem?

[Big Bronze Rim]

The clutch wont engage if the system is low on refrigerant. Is the system low/empty?

[mrmephistopheles]

whoa BBR!
Didn't even know you were here!

[Big Bronze Rim]

whoa BBR!
Didn't even know you were here!
Whats up man, I have lurked here a long time but was more active of FA. It seems though now as its kinda gone downhill and I needed to expand a bit. Hope to help out here as much as I can.

[mrmephistopheles]

right on, happy to have you here.
:bigok:

[ManoNegra]

What's up with FA? Haven't been there in ages.

[Neejay]

The clutch wont engage if the system is low on refrigerant. Is the system low/empty?
Would being low on refrigerant also cause the a/c fan not to come on? Mine hasn't come on since I bought the car 2 years ago...heh.

[timtiminy]

okay well since it doesnt engage would the light on the ac button not come on when pressed on? and arent you suppose to run the compressor when refilling with coolant, how would that work since the clutch doesnt engage?

[Big Bronze Rim]

Yes, being low on refrigerant will prevent the system from turning on. This will occur if the pressure is below the trigger point of the dual pressure switch(breaks the circuit to the clutch if pressure is too high or too low).
Again, yes you have to run the compressor when charging the system. This is acchieved by "can charging" the system to bring the pressure up to the point that you trigger the pressure switch and the compressor will cycle on. Basically you tap a can of refrigerant and invert the can, open the low side on the gauge set and let it enter the system. Whatever it will take from that one can is usually sufficient to get the system to cycle on.

[90S13dude]

I just got mine charged. Worked one day and now the light wont come on or anything. If you figure it out let me know.
Chris

[timtiminy]

just recharged my system, everything is Fab, working great! thanks!

[S13Eye]

Yes, being low on refrigerant will prevent the system from turning on. This will occur if the pressure is below the trigger point of the dual pressure switch(breaks the circuit to the clutch if pressure is too high or too low).
Again, yes you have to run the compressor when charging the system. This is acchieved by "can charging" the system to bring the pressure up to the point that you trigger the pressure switch and the compressor will cycle on. Basically you tap a can of refrigerant and invert the can, open the low side on the gauge set and let it enter the system. Whatever it will take from that one can is usually sufficient to get the system to cycle on.

Just for reference, don't try charging the system that way. Inverting the can will cause liquid refrigerant to flow into the low side. Only charge through the low side with gas, not liquid. Liquid is not compressible and you risk hydrolocking the compressor, and consequently destroying it. Charging does not have to be done with the compressor on. With the A/C OFF, and i stress the OFF part, attach the refrigerant can to the high side, invert the can and fill the hot side with liquid. If you run the system with the can attached to the high side, it will explode, and you will be severely dead or brutally mutilated. Actually, don't try doing this yourself unless you are experienced/certified/or otherwise qualified to service refrigeration systems.

If your system is out of refrigerant, it will not engage the compressor at all to prevent damaging the compressor. You can also assume that there is air in the system, so the whole thing has to be evacuated, then checked for leaks and only then it can be recharged with refrigerant. Its also a good idea to replace the reciever drier, or whatever other dessicant device you have, when the system has not been functional for a while.

[Big Bronze Rim]

Just for reference, don't try charging the system that way. Inverting the can will cause liquid refrigerant to flow into the low side. Sorry for any confusion, you definitely dont want to charge with a liquid fill while the compressor is running. And like you said you NEVER want to open the high side to the can while the compressor is running.

[Neejay]

Man...all that sounds too complicated. I think I'll just pay someone to do it all :( :(