The AC low side port on a 1999 Cadillac DeVille is against the firewall. It is on the larger of the two hoses going to the AC compressor.
If you are looking for the place to put the freon, it is the port closest to the front of the grill.....Left hand side.
Its on the suction hose right next to the accumulator...
Where is the a.c service port located
By plugging a scan tool into the service port.
Find the low side ac port on the 1999 DeVille and connect an ac gauge and freon tank. Start the engine, turn the ac on high, and open the freon valve. Let the freon flow until the gauge reads full.
You add refrigerant to the vehicle ac system through the low side port. All vehicle are so there is a website with helpful information about your vehicles ac system, including with the low side port is locateded www.idqusa.com
Edmund Port died in 1986.
Connect a freon gauge and freon can to the low side ac port. Start the engine and turn the ac on high. Open the valve to allow the freon to flow until the gauge reads full.
The EVAP Service port is on the firewall on the passenger side, right next to the low side service port for the A/C.
Connect a freon gauge and tank to the low side ac port of the 97 DeVille. With the engine running and the ac on high, open the freon valve. Shut the valve when the ac gauge reads full.
You can find the low side air-conditioner in service port on the top of the air conditioner compressor. The low side service port is also known as the low pressure service port.