My airconditioner works just fine when I am driving at a constant speed. The problem is when I am stopped, the a/c kicks on off at a rapid rate, like someone firing a gun.

When I am stopped and the a/c compressor turns off automatically, the car is idling fine at around 700-800 rpm. When the comptuer kicks the compressor on, the car idles down to around 500-600 rpm or so and then starts firing on and off.

Any ideas? Thanks

 

What year Civic is it?

 

If you have an 08 Civic, as suggested by your screen name, then take the car to the Honda dealer for warranty service.

 

Most likely, the condenser fan is not working.

When excessive pressure occurs due to condenser overheating, a safety switch turns off the compressor. Then the pressure falls, so it cycles on and off rapidly. When the car is moving, that forces air through the condenser and keeps it cool even without the fan.

The other possibility is the engine is idling too low, the computer detects that it is about to stall and cuts off the compressor. You can resolve that by pressing the gas slightly with the car stopped. If the compressor continues to cycle on and off rapidly it's not an idle issue.

 

If your Civic is a 1992-1995, there are two relays under the hood attached to the right side of the core support. One is the condenser relay and one is the compressor relay. If one or both go bad, you get problems with the AC. On my old 92, the compressor relay was going out and the AC would only work if something bumped the relay, like hitting a speed bump or tapping it before I drove somewhere. It would randomly cut off and on. I swapped them to troubleshoot and ended up having a pressure spike in the system, which blew my compressor. (So don't do that if you have a 5th gen.)

 

it's a 1999 civic lx - non vtech

 

Well, does the condenser fan fail to turn ON when you push the A/C button?

 

The compressor works, the condenser fan works. Everything works. No leaks or anything.

The problem is when I come to a stop. The car will come to idle. Afterwards, the compressor will start to kick on and off rapidly like someone firing a gun. When the computer turns the compressor off, the car will idle like normal at about 700-800 rpm. When it's time for the computer to turn the compressor on, the car will idle down to 500-600rpm and then compressor will go crazy kicking on and off. After I start driving again, the rapid firing will stop.

And while driving around town, the compressor seems to have trouble cooling the system, but when I get on the highway it seems to correct itself and the a/c works perfect.

weird i know

 

Does the condenser fan have the same rapid ON-OFF behavior?

Is the CEL ON?

Have you checked the refrigerant pressures on the high and low sides?

Is the A/C belt loose?

 

the condenser fan doesn't have the same rapid ON-OFF behavior.

the cel is not on

i'll check the a/c belt and get back with you. I am thinking that my idle might be the problem. i'll look into that as well. I might clean it out and see if that helps.

thanks for the ideas