A/C cycles

90blkbrd

Registered User
I have had my SC in for service 3 times in the last year for AC related problems. Now the 12 month/12K warranty is up.

The dealership retrofitted the system to 134a and replaced the compressor.

I went to use the AC last week and it didn't work. I bought a recharge kit and recharged the system.

Now when the compressor kicks it it will pull the motor down. Then a couple of seconds later it will kick out. Then it will kick back in. After 2-3 cycles of this happening the engine dies.

Any help/advice would greatly be appreciated.

Michael
 
Well, I've only done A/C once, and that was with some help, but you would probably need to pull about 28'' of vac. before attempting to put in any more freeon.

Also, might want to replace the lower a/c tube that goes from the condensor to the evaporator. Inside that line is an orifice valve. It can get clogged.

because your a/c worked before, and now doesn't, (but the pump still comes on), you more than likely have a leak. finding that leak should be your first priority.

I've heard people grumble that Ford a/c connections are for crap, supposedly GM has a better connection that doesn't use spring retainers and o-rings.
 
Mike is right, recharge kits only work to replace the freon in the system. Professional service includes removing the freon / recycling, pumping the system down to vac, checking for the leaks that cause the problem, and then re-pressurize. My 93 has also had the retrofit to 134a and does not seem to cool as well as the old r12. The cycling could mean low freon or simply a diluted freon mixture with possibly to much oil in the system. The orifice valve and or dryer could also have a problem.
 
ruswin said:
My 93 has also had the retrofit to 134a and does not seem to cool as well as the old r12.
If you didn't change out the condenser, that could be one reason. The original R12 tube-n-fin doesn't pull enough heat out with r134a and if combined with a restricted Otube, it works poorly. The smaller tube serpentine model will work better. There's no simple way to tell which Otube you have other than cutting the liquid line open, but there is a kit which is supposed to allow you to swap it out. :)
 
As for the stalling out, I'd check 1st off that the engine mounts are in good shape before anything else. Then check the pressures. You need to buy/borrow a set of guages to do this. A restriction in the lines or the condenser will cause the high side to go way up. Check 3 things with the engine idling at about 1500rpm: high side pressure, low side pressure, outside air temp. Hi side should be about 3x the air temp, low side should cycle to the 20s.
 
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