AC problem. Compressor Cuts on then off every 5 seconds.
Thread Starter
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
AC problem. Compressor Cuts on then off every 5 seconds.
The AC on my 95 is not blowing cold air. I start the engine with the AC on high and the compressor trys to turn on every 5 seconds but cuts off immediately. You can see the compressor engage then cut off after a second. This repeats every 5 seconds. I attempted to recharge the system with one of the DIY kits. The pressure reads about 30-35 psi with the can closed. When I open the valve the pressure increases with the compressor attempting to engage. you can see it go up to 50psi when you hear the compressor attempt to engage. I only hooked up one 18oz can and it still feels full. Did I not allow it enough time to recharge? Should I leave it connected longer? I was concerned about overfilling the system when I saw it shoot to 50psi with the compressor cycling. You are supposed to recharge it with the engine running and AC on high correct.? I am at a loss here. This recharge kit did not come with very good instructions. Anyone know whats going on?
What about testing the high and low pressure switches? How do I go about doing that and where are they located. I think I may have found one of them.
Thanks
What about testing the high and low pressure switches? How do I go about doing that and where are they located. I think I may have found one of them.
Thanks
Last edited by rickneworleansla; May 17, 2009 at 04:04 PM.
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
SunCr will probably chime in and give you a better answer, but I think you're compressor is kicking on and off because the low pressure cutoff switch is telling it that the pressure is too low.
Final pressure on the high side should be approximately 2.2 to 2.5 times the ambient temperature.
I bought a A/C gauge set from Harbor Freight. It does the job well enough. I have an '85, so I can't help on the location of the high and low side ports for your car... However most 134a cars have a blue cap on the low side and a red cap on the high side.
Click Here to see what I did to fix the a/c on my car.
Final pressure on the high side should be approximately 2.2 to 2.5 times the ambient temperature.
I bought a A/C gauge set from Harbor Freight. It does the job well enough. I have an '85, so I can't help on the location of the high and low side ports for your car... However most 134a cars have a blue cap on the low side and a red cap on the high side.
Click Here to see what I did to fix the a/c on my car.
Last edited by mikey whipreck; May 17, 2009 at 04:17 PM.
Thread Starter
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
SunCr will probably chime in and give you a better answer, but I think you're compressor is kicking on and off because the low pressure cutoff switch is telling it that the pressure is too low.
Final pressure on the high side should be approximately 2.2 to 2.5 times the ambient temperature.
I bought a A/C gauge set from Harbor Freight. It does the job well enough. I have an '85, so I can't help on the location of the high and low side ports for your car... However most 134a cars have a blue cap on the low side and a red cap on the high side.
Click Here to see what I did to fix the a/c on my car.
Final pressure on the high side should be approximately 2.2 to 2.5 times the ambient temperature.
I bought a A/C gauge set from Harbor Freight. It does the job well enough. I have an '85, so I can't help on the location of the high and low side ports for your car... However most 134a cars have a blue cap on the low side and a red cap on the high side.
Click Here to see what I did to fix the a/c on my car.
Should I be worried about overfilling the system? Is that possible? I did not leave the recharge can connected for 15 minutes as suggested because I saw the pressure spiking to 50psi with the compressor cycling.
Pro
Joined: Jun 2008
Posts: 610
Likes: 1
You're short cycling because you need coolant. The pressure reading with the can closed will go down as you add coolant. You will notice the line where you have the hose attached getting cold, and the compressor will stop cutting in and out.
Thread Starter
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
Thanks for the help everyone!
Drifting
Joined: Aug 2004
Posts: 1,294
Likes: 295
From: Galveston & Belton Texas
The compressor can also cycle like this if the orifice tube and/or condenser is restricted. It would normally show up by having high high-pressure and could have a normal low pressure condition. Instead of the low pressure cycling the compressor, the high pressure cutout shuts it off and then the low pressure turns it right back on. If you had this condition, it is possible for the compressor to get starved for oil! If a compressor destroyed itself this way, you will have lots of metal in the system. And, simply replacing a compressor won't fix a metal riddled system. Not trying to alarm you and you probably don't have this situation. I just think someone with a set of guages should confirm all is well on both the low and high sides.
Melting Slicks
Joined: Dec 2004
Posts: 2,954
Likes: 2
From: Obama=death for America
If you do have a leak, then besides losing freon, R134A - whatever, your system is taking in moisture. And you must evacuate the system when you fix the leak or your system will never be as cold as it should.
