94 Chevy Air Conditioner Problems

[mabowens]

My A/C stopped working. The compressor stays on at idle but kicks out when accelerating. The high pressure line freezes up coming out of the condenser all the way to the evaporator. High side pressure holds at 225 and low pressure side holds at 30. Any ideas of what the problem is? Thanks

[MT-2500]

Need pressure readings at idle and at 2K rpm.

[jyount]

Originally Posted by mabowens

My A/C stopped working. The compressor stays on at idle but kicks out when accelerating. The high pressure line freezes up coming out of the condenser all the way to the evaporator. High side pressure holds at 225 and low pressure side holds at 30. Any ideas of what the problem is? Thanks

Sounds like you have a restriction in the line from the condensor to the evaporator, or in the condensor itself. The freezing up is from a pressure drop. Temperature of the system at certain points is the best a\c diagnostic there is. Usually when there is trash, restrictions in the lines, especially before the accumulator, your compressor is coming apart.

[jdmccright]

What is freezing is water that has gotten into the system and is the result of the dessicant in the accumulator that has broken down and no longer able to remove water from the refrigerant. Pieces of the dessicant may also be clogging the lines.

As MT suggests...we need pressures at both rpms. If it rises at the higher rpm, then it may be cutting out due to the over pressure switch, but should cycle on/off as the pressure drops.

[j cAT]

Originally Posted by mabowens

My A/C stopped working. The compressor stays on at idle but kicks out when accelerating. The high pressure line freezes up coming out of the condenser all the way to the evaporator. High side pressure holds at 225 and low pressure side holds at 30. Any ideas of what the problem is? Thanks

the pressures at idle look too low....at about 1200rpm the low side pressures may drop so low that the compressor is commanded to turn off...


if this is the case add more refrigerent to the system...45psi low and 325psi high at 1200-1800rpm...@air temp of 80-85 degrees with the fan to max windows open...


If you had air in the system the low side would be low and the high side would be very high , much higher than your readings...