I have a 93 XJ. I am trying to recharge my AC. I already have the conversion to R-134a.
Now looking at the back of the AC pump there is an upper line and a lower line. What one is the low pressure line?

Any info would be helpful!!

 

You might want to take it to a professional.

 

The line from the firewall is the low pressure line. It's usually larger than the high pressure line too.

 

Thanks for the info!!