Help!! Air Conditioning stops.
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 23
Likes: 0
From: Eureka Ca.
Help!! Air Conditioning stops.
Air conditioning stops and won't work.Took it to a shop and was told the conversion to the new 124 type in stead of R-4 causes the ECM to cut out the air when it detects a pressure spike either high or low.
A quick fix is to disconnect the battery and re-connect and everything will be ok for a while.The problem being I can not use my air conditioning to control my primary fan.
Have any of you had a problem like this and can you give me a cure?
A quick fix is to disconnect the battery and re-connect and everything will be ok for a while.The problem being I can not use my air conditioning to control my primary fan.
Have any of you had a problem like this and can you give me a cure?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Help!! Air Conditioning stops. (rhooven)
If the pressure is too low, the solution should be simple - add some gas. If it's too high; then something is obstructed or it may have a mixture of R134 and R12 which will raise your pressures to astronomical levels. That being the case, be glad the pressure switch is there to keep it from blowing up. You need to put a set of manifold gauges on it to know what the pressures are. I'd take it to another shop. A good one should be able to tell you what's in it and check pressures for a small fee (though if there is a mixture of gas, they may not want to contaminate they're machinery so that may leave it up to you to get it out).
Le Mans Master
Joined: Oct 2002
Posts: 7,178
Likes: 1
From: Bahston Mass.
Re: Help!! Air Conditioning stops. (rhooven)
Mine is cycling every 10 seconds or so, now, so I know I'm low on freon.. I'll head in the next couple of weeks for a re-charge.. I can actually FEEL it effecting my idle around 2k RPMS.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Help!! Air Conditioning stops. (JB666)
You have R134 in that '95 so it should be fairly inexpensive to get it charged. Have it leaked check too, though after 9 years, the system is pretty tight if it's only lost a lb or less.
Racer
Joined: Feb 2004
Posts: 265
Likes: 1
From: Irwindale Ca
Re: Help!! Air Conditioning stops. (rhooven)
your local auto parts store should sell a pressure gauge and some R-134 refrigerant and oil mix. Connect the pressure gauge to the low pressure port, usually on or near the drier, it has a blue cap. When the vehicle is stopped, it will read in the red and when the vehicle is running , it should read normal pressure. While running, if pressure is low, the clutch will dissengage automatically. I think that is what is happening. If you want to add refridgerant and oil to your system, place the R-134 can upside down, and fill. If you want to boost pressure, place can right side up while filling with pressure. Watch the pressure needle. Fill until properly pressurized. Or you can take it to a mechanic... :smash:
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 23
Likes: 0
From: Eureka Ca.
Re: Help!! Air Conditioning stops. (SunCr)
Thanks, but the change over was done a year and a half ago.The shop checked all of the pressures and told me all was well.I've heard that there is a sensor near the front of the car that tells you the outside temp. and if this fails it will make the ecm kick off the air.Any ideas on this one?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Help!! Air Conditioning stops. (rhooven)
93 uses a pressure sensor that communicates with the PCM for fan and compressor control. If the pressure is too low - loss charge, system shuts down and a trouble code is set. If it's too high - above 430 psi, system shuts down. Pressure signal is communicated with serial data so if you have a scanner, you can see what the pressure is. To get it running again - even if the problem is fixed, you need to clear the code by disconnecting the battery. Outside temp sensor is used with the inside or sun temp sensor to control blower speed and how much heat is mixed with the chilled air. If it's shorted or open, an LED should be flashing and a/c may not work, but they rarely fail. If you had it converted, I presume it's because the original charge leaked out? If so, was the leak fixed?
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 23
Likes: 0
From: Eureka Ca.
Re: Help!! Air Conditioning stops. (SunCr)
SunCr,
Thanks for staying with me on this one.When checked at the shop the pressure was a little high according to the tech.The conversion was done on 6/15/02 so I would think the leak was fixed or it would have lost pressure some time back.
After he checked all of the pressures the air was still shut down so we disconnected the battery for a second.When the battery was hooked up the air conditioning worked for two days in very hot weather.And then it went out again.After doing my thing again with the battery it is back on now.
The tech. told me that 123R is not compatable with the ECM on GM cars of this vintage.This I dought as it has worked for the last two years.
Again,thanks for your help.I was hoping it would be something simple.I live on the coast and don't use the car during the winter so it has not been driven for 6 months.My first trip to the sun and my problem starts.
Thanks for staying with me on this one.When checked at the shop the pressure was a little high according to the tech.The conversion was done on 6/15/02 so I would think the leak was fixed or it would have lost pressure some time back.
After he checked all of the pressures the air was still shut down so we disconnected the battery for a second.When the battery was hooked up the air conditioning worked for two days in very hot weather.And then it went out again.After doing my thing again with the battery it is back on now.
The tech. told me that 123R is not compatable with the ECM on GM cars of this vintage.This I dought as it has worked for the last two years.
Again,thanks for your help.I was hoping it would be something simple.I live on the coast and don't use the car during the winter so it has not been driven for 6 months.My first trip to the sun and my problem starts.
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Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Help!! Air Conditioning stops. (dwestsr)
R134 operating pressures are a little higher than R12, but they shouldn't be enough to shut it down. Low pressure switch should be set to cycle the compressor off at 22.5psi and you want the high side to be 2.2 to 2.5 times the outside air temp which even at 100 degrees is only about half of the high side threshold for cutoff. Since the BAR requires a California a/c shop to note pressures, rpm and outside air temp on the invoice, what were they? The shop didn't have a scanner did it? This maybe a situation where you need to hook up the gauges and then capture scan data to find out what's causing it to shut down. It could be that the pressure switch is sending a high signal to the ECM which would show up on the scan. Solution would then be to replace the switch, assuming the manifold gauges showed close to normal pressures. I'll try to find out what that voltage signal is. I believe it's a 5 volt reference, but I'll need to check a few resources first.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Help!! Air Conditioning stops. (SunCr)
As best as I can tell, it's a 5 volt reference signal on the gray wire with a variable return on the red/black. Low pressure/low voltage - high pressure/high voltage, so when it quits working, and absent a scanner, you might want to see how many volts are on this wire. I couldn't find a pressure/voltage chart. You might ask the guys who run the Board at http://www.ackits.com - also, no Bulletins re the PCM being incompatible with an R134 retrofit. I'd think GM would say something if it doesn't work.
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 23
Likes: 0
From: Eureka Ca.
Re: Help!! Air Conditioning stops. (SunCr)
Thanks,
Sounds like I need to make an appointment with my dealer as it will need to be recharged after changing the switch.Your correct,the tech. did not have a scanner.will I need to have the system in the non operating mode to have any codes show?
The mechanic did say it would probably do it again when the engine got hot.The gauge did reach 230 while waiting at a stop sign.Usually I would have the air on and the fan would have kicked on long before the 228 degree fan startup.
I might just let idle for a while and see if I can heat it up enough to kick off the air.I'll let you know the outcome.
Sounds like I need to make an appointment with my dealer as it will need to be recharged after changing the switch.Your correct,the tech. did not have a scanner.will I need to have the system in the non operating mode to have any codes show?
The mechanic did say it would probably do it again when the engine got hot.The gauge did reach 230 while waiting at a stop sign.Usually I would have the air on and the fan would have kicked on long before the 228 degree fan startup.
I might just let idle for a while and see if I can heat it up enough to kick off the air.I'll let you know the outcome.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Help!! Air Conditioning stops. (rhooven)
Absent control of the a/c switch, I believe the '93 turns on the primary fan at 219 (off at 208); secondary on at 228 (off at 217). Gauge can be off - a scan will show what signal the PCM is receiving from the coolant temp sensor - hope it's something simple to get it all fixed (like the high pressure switch) - one of my resources show it's on a schrader so it doesn't have to be discharged - another says you got to suck it all out!
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 23
Likes: 0
From: Eureka Ca.
Re: Help!! Air Conditioning stops. (SunCr)
SunCr,
Thanks for all of your info.you have been a lot of help.I'll let you know what the results are.After looking at all the information I tend to think it will be the switch.Hope everything goes well for you down south of me. :cheers:
Thanks for all of your info.you have been a lot of help.I'll let you know what the results are.After looking at all the information I tend to think it will be the switch.Hope everything goes well for you down south of me. :cheers:
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 23
Likes: 0
From: Eureka Ca.
Re: Help!! Air Conditioning stops. (SunCr)
Check out http://www.idavette.net click on HVAC diagnostic codes. :hurray:
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