1992 grand am ac problem

I feel stupid for askig this but... I cant find the low side service port. From what I read and had people tell me it should be able to be seen from under the front of the car. I have traced the line from the compressor to the fire wall and the line from the fire wall to the accumulator and the line from the accumulator to the condensor but still have had no luck. there are two high pressure ports that are easy to find. Does any one have a diagram,picture or knows where this port is at? :confused:

you have a 6 cylinder? it should be on the suction side of the compressor, try putting your hands on the line while tracing it, you should be able to find it...

Sorry I should have listed the engine, it is the 2.3 sohc 4cyl. I got hold of two local pontiac dealers today,one said they could not find the low side port on their diagram(they could find the two high sides) the other said it is by the firewall, on the line to the accumaltor.
I searched this line carefully and still coud not find it. any other suggestions?:eek7: