Hi,
I've got a 1995 850 and my A/C is not working. I retrieved the codes from the B1 port, 1-2-4/1-2-6, for the cabin temp sensors. Removed them and they were full of dust. Cleaned them up good, started the car and they worked great. Cleared codes. Still no A/C. Retrieved codes again, same two. If the fans are working, why am I getting codes that they are not? My temp reading on the dash has been showing some wrong temps, could this be the problem?
Next I jumped compressor from the battery and it ran strong so I know that's okay. What could be the problem for the compressor not running on its own? Are there any sensors, switches or relays I should be checking? I'd sure like to figure this out and not have to spend a gazillion dollars at the dealer. Any info/help will be appreciated. I'm not a mechanic so your expert advice is welcomed. Thanks!!
1995 850 Dreaded A/C Woes-Your Expert Advice is NEEDED
Its probably the evaporator has developed a leak. Have you checked the system for pressure? The compressor won't come on if there is no pressure in the system. There should be about 40psi +/- at the low pressure side.
2004 XC70
2005 S60 2.5T AWD (gone)
1996 850 GLT Wagon in Blue (gone)
1996 850 GLT Wagon in Green (gone)
2005 S60 2.5T AWD (gone)
1996 850 GLT Wagon in Blue (gone)
1996 850 GLT Wagon in Green (gone)
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Ozark Lee
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Until you verify that you have enough R134A in the system you should avoid running the compressor for more than a few seconds or you could damage it.
Your first step is to verify the refrigerant pressure. With the compressor off it should be around 100 to 110 lbs. Most people don't have a gauge set but most auto parts stores sell a R-134A recharge kit that has a gauge built on to the can. I'm not sure how high the pressure reads on the can type gauge but if you do have a good charge it will read well into the red with the compressor off. If you have no pressure then you have a large leak in the system, the usual places are the evaporator or the accumulator. You will need to determine where the leak is and make the appropriate repair before you go any further.
If the system has pressure but it is low, like 50-60 lbs, with the compressor off you simply need to add R-134A to the system until the compressor kicks on and draws more refrigerant. The system pressure will vary with temperature but around 30 lbs. is in the ball park and the system should cool and be happy. This condition is usually due to a slow refrigerant leak and, after time, you may need to top it off again to keep it running.
If your pressures are OK you next need to check the pressure switch. A good test for it is to unplug it and simply jumper the connections in the plug. If the compressor runs and you pressure remains good then you have a bad pressure switch and you should change it.
If the system still won't run you need to check the A/C relay which is located behind glove box. Usually verifying that it clicks when the A/C is turned on is sufficient and it will at least tell you that is is getting the signal from the climate control head to turn on the A/C. If it clicks when you turn on the A/C check the voltage on the Blue/Gray wire on the pressure switch for 12ish volts. If it is not there it points toward an internal fault in the A/C relay.
...Lee
Your first step is to verify the refrigerant pressure. With the compressor off it should be around 100 to 110 lbs. Most people don't have a gauge set but most auto parts stores sell a R-134A recharge kit that has a gauge built on to the can. I'm not sure how high the pressure reads on the can type gauge but if you do have a good charge it will read well into the red with the compressor off. If you have no pressure then you have a large leak in the system, the usual places are the evaporator or the accumulator. You will need to determine where the leak is and make the appropriate repair before you go any further.
If the system has pressure but it is low, like 50-60 lbs, with the compressor off you simply need to add R-134A to the system until the compressor kicks on and draws more refrigerant. The system pressure will vary with temperature but around 30 lbs. is in the ball park and the system should cool and be happy. This condition is usually due to a slow refrigerant leak and, after time, you may need to top it off again to keep it running.
If your pressures are OK you next need to check the pressure switch. A good test for it is to unplug it and simply jumper the connections in the plug. If the compressor runs and you pressure remains good then you have a bad pressure switch and you should change it.
If the system still won't run you need to check the A/C relay which is located behind glove box. Usually verifying that it clicks when the A/C is turned on is sufficient and it will at least tell you that is is getting the signal from the climate control head to turn on the A/C. If it clicks when you turn on the A/C check the voltage on the Blue/Gray wire on the pressure switch for 12ish volts. If it is not there it points toward an internal fault in the A/C relay.
...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
I have a similar problem and I suspect the ac relay. How do you get to it and what is the part number to replace. Where can I find a new A/C relay. I do not hear any clicking when I turn on the A/C. Fan works properly, blowing hot air, compressor not kicking in.
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