valbets1 Posted July 9, 2007 Share Posted July 9, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? Quote Link to comment Share on other sites More sharing options...
wwest Posted July 9, 2007 Share Posted July 9, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. Quote Link to comment Share on other sites More sharing options...
RFeldes Posted July 9, 2007 Share Posted July 9, 2007 Also make sure the rpm sensor is connected under the compressor. Quote Link to comment Share on other sites More sharing options...
Harky Posted July 9, 2007 Share Posted July 9, 2007 My 96 has several fuses for the A/C system. Perhaps your 90 does also... Any one of them may prevent normal operation if open. I would expect a fuse for the compressor clutch circuit. Main input to the AC relay. (I don't have apositive ID on my car) There is a fuse in the A/C - climate control circuit. (This is a 15A fuse marked ECU-B in JB2 on mine) There is a fuse in the servo (air mixing) valve circuit that could possibly be the problem (20A fused marked HEATER in JB1) Bottom line...check ALL of your fuses. Is is possible that something got shorted during your compressor swap... Good luck. Quote Link to comment Share on other sites More sharing options...
valbets1 Posted July 12, 2007 Author Share Posted July 12, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? Quote Link to comment Share on other sites More sharing options...
wwest Posted July 12, 2007 Share Posted July 12, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? "Fine" bubbles just enough to make the sight glass opaque? Transitions from empty to obvious bubbling and then to "fine" bubbles, just enough to make the sight glass look grayish..? Turn the blower speed down to the lowest level which should reduce the rate at which the refrigernat is exhausted, used up, and see if the sight glass now trnasitions to liquid. If so more charge is needed. But be aware that the compressor may cycle off quickly due to high pressure limit with little "use" of the refrigerant. Quote Link to comment Share on other sites More sharing options...
valbets1 Posted July 12, 2007 Author Share Posted July 12, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? "Fine" bubbles just enough to make the sight glass opaque? Transitions from empty to obvious bubbling and then to "fine" bubbles, just enough to make the sight glass look grayish..? Turn the blower speed down to the lowest level which should reduce the rate at which the refrigernat is exhausted, used up, and see if the sight glass now trnasitions to liquid. If so more charge is needed. But be aware that the compressor may cycle off quickly due to high pressure limit with little "use" of the refrigerant. Is there a certain high and low preasure reading? I have 45 psi on the low and 170 psi on the high at about 75 deg ambient temp. Quote Link to comment Share on other sites More sharing options...
wwest Posted July 13, 2007 Share Posted July 13, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? "Fine" bubbles just enough to make the sight glass opaque? Transitions from empty to obvious bubbling and then to "fine" bubbles, just enough to make the sight glass look grayish..? Turn the blower speed down to the lowest level which should reduce the rate at which the refrigernat is exhausted, used up, and see if the sight glass now trnasitions to liquid. If so more charge is needed. But be aware that the compressor may cycle off quickly due to high pressure limit with little "use" of the refrigerant. Is there a certain high and low preasure reading? I have 45 psi on the low and 170 psi on the high at about 75 deg ambient temp. Good readings insofar as I know. Why are we pursuing this line? Because your compressor runs continuously? That may be somewhat normal depending on circumstances. Quote Link to comment Share on other sites More sharing options...
valbets1 Posted July 13, 2007 Author Share Posted July 13, 2007 I have a 1990 ls 400 with new ac compresser and i still have a blinking ac light. I can jump the compresser and it cools just fine, could this be a relay? The system protects the compressor by not allowing it to run if the refrigerant is too low. Search for "bubbles" and "sight glass" for a method to check refrigernat level. I have a steady stream of fine bubbles in the sight glass. charged with 36 oz. of freon. Could it still be to low on charge? "Fine" bubbles just enough to make the sight glass opaque? Transitions from empty to obvious bubbling and then to "fine" bubbles, just enough to make the sight glass look grayish..? Turn the blower speed down to the lowest level which should reduce the rate at which the refrigernat is exhausted, used up, and see if the sight glass now trnasitions to liquid. If so more charge is needed. But be aware that the compressor may cycle off quickly due to high pressure limit with little "use" of the refrigerant. Is there a certain high and low preasure reading? I have 45 psi on the low and 170 psi on the high at about 75 deg ambient temp. Good readings insofar as I know. Why are we pursuing this line? Because your compressor runs continuously? That may be somewhat normal depending on circumstances. pursuing because my compressor runs for about 10 seconds and then shuts off giving me the blinking green light. Quote Link to comment Share on other sites More sharing options...
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