System was fully functional last time used but has not been used at all now for some years. This a/c system has never been opened up nor has it ever been operated using defrost mode which requires the operation of the compressor. At this point in time is there any hope for resurrecting this a/c without spending a fortune and if so what steps should be taken? Any insight would be much appreciated!
A/C system not working
- Thread starter 01CuHed
- Start date
I'm no expert, but I think this is a case where taking it to a shop with the equipment to test your system is a good idea. They'll insert a dye and check it for leaks.
Once you get it working, it's a good idea to run it periodically year round. That keeps the oil in the system circulated.
Once you get it working, it's a good idea to run it periodically year round. That keeps the oil in the system circulated.
Thanks guy's for the insight! I've been trying to research a/c information on the internet and have read where the o-rings more than likely go bad along with the compressor if not used regularly? Seems kind of hard to believe that a compressor can turn to trash simply because it was not used. The fan blower works on all the different speed settings. I know absolutely nothing about a/c systems so I probably need a shop to test it out and hope for the best. I'm just afraid it could possibly be something simple and cheap but that's not what the shop will tell you? Ha!
If you wanted to just spend some time and a couple bucks, you can rent manifold gauges from Autozone using their free tool rental. That can at least tell you where to start. I think A/C work is an interesting project to tackle because it's both science and "hands-on." You have to calculate, think, deduce. While I wouldn't want to do it every day, it's interesting when it all gets fixed and aside from the evaporator, it's all easy to get to.
Right off the bat the shop is going to check pressures & want to bill you for an evac & recharge which is usually around $100. They may also inject some UV dye into the system to look for leaks. From there it might work like a champ or it will identify other problems that require replacement.
Have you looked over your AC lines for signs of refrigerant leakage? Refrigerant is greasy because of the oil that's in it, if there's a hose or fitting that has allowed the refrigerant to leak out over time you'll usually see the surrounding area covered in an oily dirt/grime mixture. Same goes for the condenser in front of the radiator, if there's a greasy spot on it it's indicative of a leak.
There are no apparent leaks of any kind from my observations anywhere. Would the system be free of contaminates since it's never been opened up? I can understand having it evac, recharged and hoping for the best but from what you read on the internet the compressor would be frozen from not being used or is that not necessarily so? Does the compressor have to be operating in order to check pressures? I have only tried once briefly to turn on system but the compressor would not engage. Maybe thru time it SLOWLY leaked out enough refrigerant that's keeping the compressor from engaging? If o-rings did have to be replaced is there an o-ring connection on the evaporator? Thank you guy's for responding...just trying to educate myself on troubleshooting A/C systems!
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Ever
Every connection in the system uses an O ring so every connection can be suspect and compressors typically do not fail from lack of use. Most common issue is naturally loss of refrigerant over time. A simple test to see if the compressor is operational would be to jump the low pressure switch leads on the harness plug for the low pressure switch. Look for an aluminum cylinder with 2 refrigerant lines near your firewall next to the heater hoses, on top should be a switch. If the compressor engages then the most likely cause is low refrigerant.
Every connection in the system uses an O ring so every connection can be suspect and compressors typically do not fail from lack of use. Most common issue is naturally loss of refrigerant over time. A simple test to see if the compressor is operational would be to jump the low pressure switch leads on the harness plug for the low pressure switch. Look for an aluminum cylinder with 2 refrigerant lines near your firewall next to the heater hoses, on top should be a switch. If the compressor engages then the most likely cause is low refrigerant.
There are many things that can stop the A/C compressor from running; the low or high pressure switch can be bad (oxidized contacts or open transducer) , the compressor clutch can be bad stuck due inactivity, the control console can have oxidize contacts.... are to name just a few.
Purchase a refrigeration manifold and VOM multi-meter from Harbor Freight; you can do a light troubleshooting yourself.
Purchase a refrigeration manifold and VOM multi-meter from Harbor Freight; you can do a light troubleshooting yourself.
The compressor does have to be operating to check pressures from a functional standpoint, but you can put a set of hoses on it & see what you have now. Since the compressor isn't operating the pressures on the high & low sides will be equal, but you'll get a reading of some sort. Ball park would be maybe 60-70 psi as it sits, but that's a ball park just based of memory.
The compressor wouldn't necessarily be frozen, but refrigerant leaking out over a period of years certainly isn't out of the question. The o-rings that are used in all the connections can dry out, crack, & eventually leak enough refrigerant to trip the pressure switch into keeping the compressor clutch from activating.
Speaking of the compressor clutch, do you hear it trying to engage when you select AC from the control panel? When the system is off you'll see the compressor pulley (the part of the pulley forward of the belt) stationary, when the system operates that same part will start spinning with the belt because the clutch is engaged. Is they pulley spinning or not when you have AC turned on?
If you're concerned with the compressor being seized you can try to spin the front part of the pulley by hand when the engine is off. See if you can turn it or if it's seized.
Info is much appreciated and consensus is pretty much what I have gathered from my research. I have read about jumping the low-pressure switch which I will try quickly just to see if compressor engages but before I do that I will check connections for corrosion. If compressor engages I will take to a shop for the evac and recharge and cross my fingers the o-ring on the evaporator doesn't need changing. Ha!
Qslim I did not hear the compressor clutch trying to engage when I attempted to turn on system. I don't remember reading about trying to turn the front part of compressor pulley by hand to check for seizure but will definitely give that a try! Ya'lls answers have given me more hope than what I've gathered elsewhere about A/C's and I will be sure to post my resolution to the problem here once figured out!
Nguzzo
Member
So I had this exact issue with my 05 2.4. Here is what I checked. A/c turned on in the cab, air blows from the appropriate setting (feet, defrost, front vents and gets harder on the recirc setting) ac pulley spins but clutch did not engage. Spent MANY hours watching YT videos and “diagnosing”.
My A/C clutch would not engage so performed the following:
- freely spun the compressor with engine off had good tension did not free spin
- checked 10a fuse with test light - all good
- checked relay with multimeter and swapped with horn relay - both good
- jumped low pressure valve harness -did nothing
- carefully power probes the clutch power coil at the compressor with engine off - engaged! But only when I gave it power
- jumped the relay at fuse box positions 87 and 30 iirc and clutch engaged with engine on and off
- swore at Jeep and took 24 hour break
- watched another video with an obscure reference that the improper pressure would not allow the system to engage
- connected recharge kit, started engine with A/C setting ON and decided to let it rip! SUCCESS! A/C clutch engaged on its own and cycled. I continued to add refrigerant following directions on the can, rotating as it dispenses. I let it run for few minutes and voila, air blowing cold!
Only cost me ~$27 for the kit at Walmart and it has the dye so if it does leak I can check with UV light. frustrating for me and I thought I was checking it all. I realized that the system had some pressure so I thought it was good but testing with engine running really gave me the true indicator that it was low. With the Jeep not running it gave me a false sense of charge due to the equalized pressure from the high side.
Hope that made sense one of my first ventures working on my, new to me Jeep.
My A/C clutch would not engage so performed the following:
- freely spun the compressor with engine off had good tension did not free spin
- checked 10a fuse with test light - all good
- checked relay with multimeter and swapped with horn relay - both good
- jumped low pressure valve harness -did nothing
- carefully power probes the clutch power coil at the compressor with engine off - engaged! But only when I gave it power
- jumped the relay at fuse box positions 87 and 30 iirc and clutch engaged with engine on and off
- swore at Jeep and took 24 hour break
- watched another video with an obscure reference that the improper pressure would not allow the system to engage
- connected recharge kit, started engine with A/C setting ON and decided to let it rip! SUCCESS! A/C clutch engaged on its own and cycled. I continued to add refrigerant following directions on the can, rotating as it dispenses. I let it run for few minutes and voila, air blowing cold!
Only cost me ~$27 for the kit at Walmart and it has the dye so if it does leak I can check with UV light. frustrating for me and I thought I was checking it all. I realized that the system had some pressure so I thought it was good but testing with engine running really gave me the true indicator that it was low. With the Jeep not running it gave me a false sense of charge due to the equalized pressure from the high side.
Hope that made sense one of my first ventures working on my, new to me Jeep.
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