Orifice tube location

2000 Bonneville SLE cant find orifice tube. Disconnected lines connecting to firewall and didnt find a tube in there. It is very hard to see but I inserted a small wire in order to feel a possible orifice tube but the wire and needlenose detected nothing. Help only car is down. I have always found the tube in the section where tubes/lines go into the firewall. I also looked along aluminum tubes for a "place where one could be extracted but I am at a loss as to where this darn tube/orifice is. I also went to a/c compressors website and nothing.165,000 miles 00SLE Pontiac Bonneville, compressor clutch went bad so I bought compressor, dryer, tube, and plan to flush lines w/cleaner(bought at Advance for a/c). And install all new components