Further investigation revealed that the fill fitting for 134A was in place where the original R12 fitting had been.

The photo you posted looks like the receiver dryer on our 1994. The 91 and 92 cars we have have a second fitting on the backside of the receiver dryer as is shown in this image (this is an unconverted non-functioning 91). It has the pressure switch in place.


Now that you directed me to the proper fill fitting and since it is for the conversion to 134A my original question is answered and I thank you. However it raises the question of what is that second port for? It used to be that two connections were needed for the AC gauges. Do they still use two hookups for gauge sets and is one larger than the other to prevent getting the low/high side switched when connecting?

And finally with no pressure switch in the system would the compressor be at risk if the freon level fell and it continued to run?

Thanks for your help.

Randy