Neither my 66 Ambassador and 72 Argosy had ever had air conditioners
installed when I bought them. Both were prewired and had the condensate
tube. You can check for the tube by looking at the wheel well area for a
short clear tube sticking out. However, neither had circuits installed for
the AC. The circuit box had a spare opening. The wiring terminated behind
the panel that box was mounted on and I had to drill out a few rivits, fish
the wire out, feed it through the circuit box, and install a new circuit.
The location for the mounting of the AC and the wiring is a certain number
of inches back from the front shell, something like 113 to 118 (Charlie
Burke can tell you), which is generally centered between the front and
middle room. I ended up using Carrier units, which are designed to sling off
condensate, and did not use a pan or the tube. I'm in a humid area (Gulf
Coast) and the runoff down the sides is very minimal.
Jarrod