Hi all, my first post on this site.
My problem is with my 95 Grand Cherokee, 4.0, auto, 178,000 miles. My AC compressor cycles on and off constantly. The clutch will engage for a few seconds then disengage for a few seconds, engage then disengage, etc. Using the K-mart freon refill with the gauge attached, when the the AC clutch is disengaged the gauge shows low (in the yellow on the gauge) and when the clutch is engaged the gauge shows full (blue on the gauge) and the air coming out of the vent is somewhat cool. I pulled the plug on the pressure switch at the compressor and jumped it. With the plug off, the clutch does not pull in as it shouldn't(which takes the pressure switch out of play), with a jumper in the plug it continues to cycle on and off. My question would be what would make it cycle like that. Any and all help would be greatly appreciated, since the temps are hitting high 90's now here in the Dakotas, might say i'm getting a little hot under the collar. Bully

 

not sure what else could be cycleing the compressor other than a hi pressure switch,has the system been operational up to this point? has it been opened up for any length of time?, weeks, months?(thinking contamination) the readings youre getting on the gauge really dont mean much as it isnt running long enough to make any determination. are you sure youre hooked up to the low side and not the hi side? the low side will be the larger size pipeing and the fitting should be close to the firewall



maybe this will help:
https://vil.motor.com/HOME_FRAMESET....47bc2b6cb3c7de

 

Ken thanks for the reply, as far as the system, it worked last season and has not been opened. And i had the k-mart special hooked to the the larger fitting in the corner by firewall. I think maybe best if i get a set of gauges and retry getting pressures. Thought maybe someone had incountered this problem before and would have the "quick fix". Bully

 

well you can try this at your own risk but you could run a jumper wire to the compressor to give it constant 12v to see if you can get it to run long enough to take the refridgerant in,also it wouldnt hurt to put a shop fan or even a window fan right in front of the rad. while youre running it