Hi,
My Mom's 94 Chev Lumina (V6 3.1 liter) A/C stopped working. In a process of elimination (see "Test Results" below), I have eliminated some things already. Note: The A/C compressor clutch doesn't engage when A/C is turned on. According to Haynes service manual, this car (3.1 liter engine) doesn't have pressure switches (I couldn't find any).
I removed the connector (3 wires) from the A/C pressure sensor. This sensor symbol in a Haynes service manual looks like a potentiometer with ground on one end, +5V on the other and a wiper arm (pressure). The wires run to the ECM. It is extremely difficult to measure the sensor resistance so I can use a regular "pot" of the same resistance to simulate the pressure sensor.
A Google search did not reveal the information I need.
Do you know any tricks to eliminate the pressure sensor?
Thanks in advance, Brad
TESTS RESULTS:
My cousin brought his A/C pressure gauge and said the pressure was normal (checked on low side) with engine running A/C on "MAX".
I checked the A/C relay in my service shop and checked the "HVAC" fuse (only fuse for AC). I disconnected the connector from the compressor clutch and checked for voltage with engine running and A/C on "MAX". No voltage.