1997 Lincoln Continental

The low-pressure service access gauge port valve is located on the evaporator to accumulator/drier suction line near the dash panel at the A/C evaporator core outlet tube.

You should have a gauge on the high side too, to get an accurate state of charge. The high-pressure service access gauge port valve is located on the condenser to evaporator tube to the right of the radiator. In the stowed position it is clipped to the A/C condenser core. Remove the clip from stowed position when servicing system.

Rob