Question : New Question on A/C?

[Jesster]

I have a 1998 Lumina 4dr with a 3100 that sat for 6 months early last year and then towards the end of summer I did a LIM replacement. The A/C worked before it got parked. I don't see any of the dusty oily leaks at seals or on hoses that would warrant repair. The low side is at around 50psi @ 80degf, the high side is around 70psi. I can't get the compressor to kick the clutch in. I would like to manually trip the compressor clutch by shorting the low pressure sensor wires. My H@ynes book says that the low pressure switch is on the inlet pipe to the evaporator. Isn' the evaporator inside under the dashboard behind the heater core? On my blazer the switch is on the accumulator (piece of cake to do). Question, what is the easiest way to kick the clutch in manually? Do I have to get at the switch under the dash?

[robertisaar]

easiest way to force it on would be to jump the relay terminals.

[55trucker]

The system low pressure cut out switch shoooooooooood be on the left side of the engine bay, near the accumulator, before the orifice tube, possibly obscured by the battery.

[pocket-rocket]

easiest way to force it on would be to jump the relay terminals.

This is the way I would attack it. The last time I tried jumping the switch the car wouldn't kick the pump on so I figured it was a pressure sensor, not switch (that and the 3 wires in the connector instead of just 2).

Sent from my HTC One X using Tapatalk 2

[robertisaar]

yeah, i think all GM stuff from 91 and upwards used pressure sensors, not switches.

[55trucker]

True....but the FSM still refers to them as *pressure switches*