Empowering Techs A/C High and Low Pressure Port Mastery

3 Symptoms Of A Bad AC Pressure Switch [HIGH OR LOW]. Mechanic Base ... GM Air Conditioning Pressure Switch Problem and Replacement!! Low pressure lines are the fatter ones, high side are the smaller lines. Don't have your year so I've no exact info. LOW, LOW, Add Refrigerant. ; LOW, HIGH, Need service, possible blockage of the expansion valve or orifice tube. ; HIGH, LOW, Needs service, possibly faulty ... I rented the gauge set at Autozone and compressor off,I had approx. 95 psi on high and low side. Compressor on, low: 45-50 high: 198-200 and ... I found one port, I assume is the low pressure port about 1 foot from the left end of the radiator. ... I switched to A/C and the air got warmer ( ... The high and low side pressure equalize when the A/C system is shut of and sat or when the compressor isnt working period. My best guess would be the Valve ... The extremely high pressure on the high side and normal pressure on the suction side indicates that the evaporator is overheating. Turned on wife's A/C in her 02 golf, and it blows out normal air - no cooling feeling at all. I was able to see that the clutch is at least spinning when... The narrower tube is the high-pressure line and the wider one is the low pressure line. Follow the wider tubing from the compressor until you ... The smaller fitting is the high pressure side. The larger fitting is low pressure side and is for charging.