95 escort a/c problems HELP!!!!!

[jostraco]

i have a 95 escort lx with about 97k mi. on it. now about 6 months ago, i spent 800 bucks for pretty much a whole new a/c system, and it was working great for the 6 months, then all of a sudden the other day, it just pretty much stopped working, now whenever i turn on the a/c, it will go on for like 30 seconds, then kick off, then back on, and so on, eventually stalling the car out. This usually happens when stopped, like at a stop sign or a red light, but still happens when driving, just not as bad. Can somebody please help?

[mightymoose_22]

Does the car run normally when the AC is off?
When the AC is on, how frequently does the compressor switch on and off? 30 second intervals the whole time?

Have you checked the system pressure to make sure the refrigerant has not leaked out?

Even though the AC goes on and off, does it get cold?

Verify that the engine will idle normally when at normal temperature with the AC turned off... then we can go from there.

[jostraco]

yea, the car does idle normally when the ac is off, its just when its turned on, and when i first turn it on, its fine for like 1 minute, then switch off, then on, but it is steady, about 30 second intervals, but sometimes a bit less, sometimes a bit more, but when it does switch on, it will get cold, but it will be about enough time for the air to finally get cold, then it will switch off again. i did check the pressure and thats another thing, the needle went into the "warning" zone on the guage that was attached to the can of freon, and im not sure how to fix that either, but im assuming that means there is too much freon, but im not sure

[mightymoose_22]

So did this problem start after having recently added refrigerant to the system?
I think your first step is to get the pressure in the AC system correct. Your pressure could either be too high or too low. You will have to figure out which.

As for the engine running rough, make sure your accessory belt is in good condition and that your alternator is putting out adequate power to take the load.

[jostraco]

well i never actually put any freon in the system, i was going to, but then the guage went into the red, so i didnt end up putting any in, it always had the same amount as when it came from the shop when i had it fixed 6 months ago. Do you think it could be a relay switch or something? im not sure how to tell if those are good or not, but i checked all the fuses and their all fine. How would i first, get the pressure correct, can i just stick like a pin or something in the valve to let some of the pressure out? and how would i tell if the alt is putting out enough power or not? i appreciate the help, thanks a lot

[Davescort97]

The cycling switch is on the receiver drier in the center of the firewall. It shuts the compressor down if the pressure gets to be less than 24. It makes the compressor come on when the pressure gets to 45 and higher. So, it would seem to me you need more freon. If you haven't added any freon since it was rebuilt, there's no way it could have too much pressure. You must have the A/C on to read the pressure on your can. 45 is the minimum to get the compressor on and stay on. Just add enough freon to keep the compressor from cycling off but don't add more than 1 can.

If I'm insulting your intelligence I apologize. The AC has a high pressure side and a low pressure side when the AC is on and the engine running. If you check the pressure with the system off you are going to get a higher reading on the low pressure side. The two sides balance out when the unit is not on. You check the pressure on the low pressure side while the engine is running and the AC is turned on full blast. It's also called the suction side. It will suck freon into the system, but only if it is on and running.
You must put freon in the system on the low side with the unit on. It'll be about 50 on the low side and 150 on the high side. If the unit isn't on you'll get a reading of about 100 on both sides.

[jostraco]

i figured out what it was, it was the clutch relay, and i know, when i checked the pressure, the car was one, air was on full blast, and i was at the right port. so i mean i do know what i am doing, but i figured it out, it ended up just being a 10 dollar relay switch. but thanks everyone for your help