I believe the obd port is located by the parking brake and just above it.
The 1996 Mercury Grand Marquis OBD 2 port is on under driver side dash next to center console
Under the dash on the drivers side.
On a 1993 Mercury Grand Marquis ( which is OBD I , EEC IV ) ( there should be an EEC TEST connection in the engine compartrment )
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.
The 1988 Mercury Cougar diagnostic port can be found under the hood.
On my '93, there is no consumer serviceable port. I think the recharge has to be done by a technician.
The OBD connector is under the dash on the driver side.
To add Freon to a 2000 Mercury Grand Marquis, locate the low-pressure service port on the AC system, which is typically found near the accumulator or the firewall. Remove the cap from the service port, attach the refrigerant gauge and hose, and then add the appropriate type of refrigerant. Be sure to check the system pressure with the gauge to avoid overcharging. Always follow safety precautions and consult the vehicle's manual for specific instructions.
On a 2001 Mercury Grand Marquis, the low-pressure service port for the air conditioning system is located on the larger diameter aluminum line, typically near the accumulator or on the firewall side of the engine. It's usually covered by a plastic cap that can be removed for servicing. Make sure to identify it correctly, as there is also a high-pressure service port in the system. Always consult the vehicle's manual for specific details and safety precautions when servicing the A/C system.
In a 1999 Mercury Grand Marquis, the low service port for the air conditioning system is typically located on the accumulator, which is found near the firewall on the passenger side of the engine compartment. It may be covered by a plastic cap, usually labeled with an "L" for low pressure. To access it, simply remove the cap and connect the service gauge or refrigerant canister for maintenance. Always ensure the engine is off and the system is not under pressure before attempting to service the AC system.
The refill port for refrigerant on a 1995 Mercury Marquis is located on the low-pressure side of the air conditioning system. You can typically find it on the larger diameter tubing that runs between the evaporator and the compressor. It is usually marked with a blue or black cap. Always ensure the system is off and follow safety precautions when handling refrigerants.
The OBD II port connector is located to the left of the steering wheel, just beneath the dash panel.