Location of low side a/c fitting on 92 E350

Does anyone know where I can find the low side a/c fitting on my 92 E350? The weather is hot and the a/c isn't doing much.

If it's like my '91 it's on top of the accumulator.
It's on the far end of the blower housing, you have to unscrew
the pressure sensor to get at the valve underneath.
It wont leak or blow out, the pressure sensor has a nib that
pressed the shrader valve when it is screwed on, whne you remove it,
the valve closes.

Thanks Starman97 for the info. I had a hunch that it was located there but I wasn't willing to take a chance and screw something up.

I also found a second fitting on the pipe that runs on the firewall, you cant see it easily because of the wiring conduit and the air intake hoses.

I took parts the fittings on the evaporator to replace the o-rings and found that the orifice tube was coated in a mixture of black particles and oil.
Commonly known as 'Black Death' it means imminent failure of the compressor. So I pulled everything for a R134 conversion. The only parts left are the condensor and evaporator cores and i'll flush them be reassembly.