A/C Compressor not cycling ??
PigBoT
05-03-2005, 08:29 PM
Hey Everyone. Ugh, I'm really bothered with this one. I have a 99 Jeep Cherokee Sport 4.0. When I turn on the A/C everything seems normal but I don't hear the compressor cycle (?). I don't even know if i'm explaining it properly or if it's a problem with the compressor. The air is definately blowing warm. I've charged the system, but perhaps I have over charged (?). Anyway, can someone give me some trouble shooting tips in lame-man terms? Or perhaps tell me what is wrong with it (assuming you understood what I was saying =\ ). Thanks! -PigBoT
sector95
05-07-2005, 08:43 PM
How do you know you've charged the system fully? And you can overcharge the system, although it will function but not at peak efficiency. IMHO, I would bring it in to a good local shop and have them run a diagnostic on it, check it for leaks and charge it correctly. I just had my system done and it cost me $70 and that included 2lbs (or cans) of 134a....
mike
mike
fergmonster
05-09-2005, 08:06 PM
Hey Everyone. Ugh, I'm really bothered with this one. I have a 99 Jeep Cherokee Sport 4.0. When I turn on the A/C everything seems normal but I don't hear the compressor cycle (?). I don't even know if i'm explaining it properly or if it's a problem with the compressor. The air is definately blowing warm. I've charged the system, but perhaps I have over charged (?). Anyway, can someone give me some trouble shooting tips in lame-man terms? Or perhaps tell me what is wrong with it (assuming you understood what I was saying =\ ). Thanks! -PigBoT
if you don't want to spend the money to have it looked at. First check and see if you have any pressure on the low pressure lines. if you do, then buy a recharge kit. anywhere from 14-35 dollars. i like the one w/screw on bottles. check the pressure with the car running, while the A/C is on full blast!!! dump som 134 in it and check for the comp. to cycle, the pressure will slightly dop on the line while charging initially but will then stabilize.
If there is no pressure on the line, then you may have a severe leak. i'd definetly take it in for a diagnostic at your local A/C shop.
Good luck, if you need anything else. let us know on here.
if you don't want to spend the money to have it looked at. First check and see if you have any pressure on the low pressure lines. if you do, then buy a recharge kit. anywhere from 14-35 dollars. i like the one w/screw on bottles. check the pressure with the car running, while the A/C is on full blast!!! dump som 134 in it and check for the comp. to cycle, the pressure will slightly dop on the line while charging initially but will then stabilize.
If there is no pressure on the line, then you may have a severe leak. i'd definetly take it in for a diagnostic at your local A/C shop.
Good luck, if you need anything else. let us know on here.
AlohaBra
05-15-2005, 12:00 AM
if you don't want to spend the money to have it looked at. First check and see if you have any pressure on the low pressure lines. if you do, then buy a recharge kit. anywhere from 14-35 dollars. i like the one w/screw on bottles. check the pressure with the car running, while the A/C is on full blast!!! dump som 134 in it and check for the comp. to cycle, the pressure will slightly dop on the line while charging initially but will then stabilize.
If there is no pressure on the line, then you may have a severe leak. i'd definetly take it in for a diagnostic at your local A/C shop.
Good luck, if you need anything else. let us know on here.
OK....I have fixed this problem (mine was 97 sport)....
First buy an R34a recharge kit with gage, some are marked where the pressure is supposed to be ...it goes on the low side of the AC with a special fitting but don't hook it up yet. Then disconnect the AC clutch power feed (by the distributor)....and jump the compressor clutch to the 12 volt positve side of the battery. Then hook your gages up (use eye protection and a rag at the fitting). Proper charge is about 30-40 psi on the low side. If it is low put some in and then check for leakage issues. If not low do not add more.
My problem was the weather pack connector to the AC clutch had a poor connection so clean it. My problem was also intermittent. Also check for 12 v. going to it with a digital volt ohm meter (dvom). If no 12v then you have a fuse or low pressure problem. While I was at it, I also checked and cleaned the compressor clutch ground screw.
I don't recommend hooking the gages up if the compressor is not running because of higher r134a pressures and could be hazdardous.
Pressure without the compressor running is about 100psi or more and will result in r134a spillage when connecting. High side pressure when running exceed 200 psi. You can tell the low side which has fatter hoses from the high side with thinner hoses. My gages hook up at the receiver dryer at the right rear of the engine compartment (oil filter side).
Once you get the compressor going and the proper charge of R134a verified then you can pursue any other issues. The low pressure switch can be jumped with a paper clip if needed to get the compressor going. Do not overcharge because liquid refrigerant can reach the valves of the compressor and even seize the pistons in the compressor up.
If there is no pressure on the line, then you may have a severe leak. i'd definetly take it in for a diagnostic at your local A/C shop.
Good luck, if you need anything else. let us know on here.
OK....I have fixed this problem (mine was 97 sport)....
First buy an R34a recharge kit with gage, some are marked where the pressure is supposed to be ...it goes on the low side of the AC with a special fitting but don't hook it up yet. Then disconnect the AC clutch power feed (by the distributor)....and jump the compressor clutch to the 12 volt positve side of the battery. Then hook your gages up (use eye protection and a rag at the fitting). Proper charge is about 30-40 psi on the low side. If it is low put some in and then check for leakage issues. If not low do not add more.
My problem was the weather pack connector to the AC clutch had a poor connection so clean it. My problem was also intermittent. Also check for 12 v. going to it with a digital volt ohm meter (dvom). If no 12v then you have a fuse or low pressure problem. While I was at it, I also checked and cleaned the compressor clutch ground screw.
I don't recommend hooking the gages up if the compressor is not running because of higher r134a pressures and could be hazdardous.
Pressure without the compressor running is about 100psi or more and will result in r134a spillage when connecting. High side pressure when running exceed 200 psi. You can tell the low side which has fatter hoses from the high side with thinner hoses. My gages hook up at the receiver dryer at the right rear of the engine compartment (oil filter side).
Once you get the compressor going and the proper charge of R134a verified then you can pursue any other issues. The low pressure switch can be jumped with a paper clip if needed to get the compressor going. Do not overcharge because liquid refrigerant can reach the valves of the compressor and even seize the pistons in the compressor up.
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