Air Conditioner Compressor Cycling On and Off

[mafiadoller]

i have a 1993 chevy silverado with a 350 and i was trying to get the A/C to run cold,i put some refrigerant in the low side and it said that it was full.now the ac blows cool but not cold and the A/C compressor turns off and on in 10 second increments.i was wondering if i need to get a new compressor or what

[brcidd]

having the pressures stated would help- but typically you are still low on refrigerant-- a gage cannot tell you if it is full- rapid cycling is an indicator of loss of refrigerant.

[j cAT]

Originally Posted by mafiadoller

i have a 1993 chevy silverado with a 350 and i was trying to get the A/C to run cold,i put some refrigerant in the low side and it said that it was full.now the ac blows cool but not cold and the A/C compressor turns off and on in 10 second increments.i was wondering if i need to get a new compressor or what

if you have the pressure at the low charge fittings and the a/c compressor clutch cycles this may be the low pressure cut out switch being out of range..see what pressure , that this switch causes the clutch to drop out..using a jumper you can test this, to be sure, the switch is not operating at the correct pressure.


what refrigerent are you using ? what is the OEM refrigerent listed for this a/c..

[mafiadoller]

i am using r1234 refrigerent(it's been converted over)

[mafiadoller]

the pressure is 45 psi, right before the yellow

[j cAT]

Originally Posted by mafiadoller

the pressure is 45 psi, right before the yellow

since this was designed for the R12 the coils , the spaces between the coils are futher apart ..this reduces cooling efficiency with the conversion R134.

the coils being clean make a big difference ..

the switch ,,,the low pressure switch ,,with your pressure guage reading the low side pressures..with this connected this should not drop out with pressures above 5-10 psi..if the compressor shuts off at pressures above 5-10 psi jump out the switch and see if the switch is causing this..these switches do fail when they have been in service a long time..

[mafiadoller]

Originally Posted by j cAT

since this was designed for the R12 the coils , the spaces between the coils are futher apart ..this reduces cooling efficiency with the conversion R134.

the coils being clean make a big difference ..

the switch ,,,the low pressure switch ,,with your pressure guage reading the low side pressures..with this connected this should not drop out with pressures above 5-10 psi..if the compressor shuts off at pressures above 5-10 psi jump out the switch and see if the switch is causing this..these switches do fail when they have been in service a long time..

i have not checked to see what the psi is when it turns on and off put i have jumped it off and the psi is 12(that's how i put the stuff in it,because it would not turn on by itself with out me jumping it off)