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.

"Brad" <bpetria@verizon.net> wrote in message
news:44cf689d.1450294@news.bellatlantic.net...
> 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.

This may not help, but I did an A/C recharge on my Grandparents '97 Chevy
Lumina with the 3.1L V6 a while back. After the system was fully charged, I
turned on the A/C, and found the compressor clutch was not on. I looked all
over the car for the reason, yet didn't find one. Finally, I realized what I
had done. In taking off the air boot (to gain access to the re-fill port for
the A/C) I had unplugged 2 sensors. After I plugged those sensors back in,
the A/C clutch and the system it self worked perfect. Ice cold.

Like I said, this may not help, but make sure the car is all hooked back up
after you are done.