'87 F-150 with R-134A . A/C is cool but not cold.
As soon as compressor cycles on, it cycles off then back on. It's gone crazy!!Put a gauge on the low side and it reads within the limits for being properly charged. According to the charts I have seen
the a/c cycle switch is kicking on/off at the appropriate levels (25 & 45 psi).
Is there another switch/sensor that could cause this problem???What's the deal?
Really loosing my cool here..ha ha..help!

 

Thanks, will keep that in mind.

When I read further today I found out that I had misunderstood what I previously read....cycle switch is functioning OK...just needs recharged on R-134a.
Did that and added some stop leak, is cooling fine now, only time will tell.

I thought the compressor was shutting off at 45psi when it was actually coming on and then kicking off because the pressure was too low. Thus it was undercharged...tah dah..!!!!

 

Arn't you happy thats all it is!!!! I can understand why you want the ac as cold as possible! IT was 94 up here in Kansas today!

 

I don't know if this will help you or not. 2 years ago my compressor R-12 kicked on and off constantly. It finally quit alltegether. It was the cycle switch. When I had it replaced the mechanic told me the switch will do that when they go bad.

 

I feel your pain! Two weeks ago my compressor was doing the same. My mechanic said it would do that when low on freon (R-134). So he added 2 lbs. and it blew ice cold for two days, then nothing! Warm air, compressor kicking on and off. He then pulled a vacuum on it and it didn't hold, hence, a leak. He then added two more lbs. of freon along with an ultraviolet dye. He ran the truck for 2 hours, still cold-48 degrees!! We went and had some beers contemplating the problem. The next morning, on my way to fix the g/f's dead battery on the side of the freeway the a/c blew warm again. (aaahhhggggrrrrr!!) I popped the hood to look for the yellow die and possibly some freon residue. Lo and behold it was all over the front of the compressor! Well, $800 later the a/c is back to blowing at 48 degrees! <sob sob> Just thought I would share my story w/ ya!

Neal

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'94 F-150, 4.9 6cyl., K&N FIPK, Mangecor 8mm wires. Gibson 3" Side Swept, MSD Blaster Coil, superchip. Just stolen: Pioneer DEH-P835R Head Unit, Rockford Fosgate 200a1 pushing 2 RF 10" subs. Pirelli Scorpion A/T 255/75/15. Est. 200 hp 300ft/lb. Torque! Not bad for a straight 6!! Also driving the girlfriend's '94 Mercury Grand Marquis.

 

Guys, My 1993 is acting up, it switches off and on at different times. Basically if you turn it on it will either come on and stay on or not come on at all. I am going in to have the 4th ac compressor cycle switch replaced again....Cheaper than a new compressor...

 

Hey JERRY07, I noticed you have R-134A in your '87. I was wondering if you got one of those conversion kits at K-Mart or something. I have been thinking about it, but, I hear they don't cool as well as R-12. Mine needs recharged (R-12), but I was just thinking of one of those. Can you tell me anything about them?