Where is the low pressure port on a 1988 ford grand marquis?

On a 1988 Ford Grand Marquis, the low-pressure port for the air conditioning system is typically located on the larger diameter aluminum line that runs from the compressor to the evaporator. It is usually near the accumulator, which is mounted on the passenger side of the engine bay. The port is often covered with a plastic cap and is identifiable by its smaller size compared to the high-pressure port.