If you connect a set of A/C gauges and see pressure, that is normal, however it does not mean there is the correct charge in it. That is because it will expand and hold the pressure that equalizes the boil off temperature of R134a. That is normally in the area of ambient temperature. So, if it's 90 degrees you would see around 90 psi in the system regardless of the amount in the system. Then if the compressor is working you would see one side drop to 40-50 and the high side will climb. Those numbers are what counts. If you want to test the compressor you can jump power to the clutch and turn it on with the engine running.
To do that look at the compressor and apply 12 volts to the Dark green wire from the battery. That should engage the clutch. Now watch the gauges and see what the pressures do. If the low side goes down and the high goes up the compressor is at least working. Then the issue is somewhere else, like a pressure switch or wiring issue. Then return and we can look into the issue from there.
Thursday, July 24th, 2025 AT 2:21 PM
