On our '72 Newport Royal, the Chrysler service manager explained the heater water valve cable routing, which is different than prior body series cars. He noted that the cable was a two-piece cable. This was needed as there was now an a/c compressor switch in the works. I had noticed that when the a/c switch was "OFF", the a/c compressor still ran.
His explanation was, which I found in Chrysler service literature, that when "OFF", nothing was really "OFF". The fan ran on a very slow speed and the compressor still ran. In "OFF", the vac to the vent system actuators was in the "no vacuum" mode, which meant air to the floor and defroster ducts. That kept the windshield from fogging quite so badly when the defroster was turned on on cold mornings, from the initial rush of moisture-laden air. I accepted that, but still didn't like the compressor running all of the time. Obvious drains on engine power and fuel economy, to me. Which made the lower power of the very low CR 400 2bbl worse.
I had noticed a click when the heat lever got to about 1/2 way to hot. THAT was the compressor switch. Seems there is a shorter cable from the control lever, to an intermediary relay bracket, and then the 2nd cable continues on to the water valve? Seems like I verified that in the '72 parts book illustrations, back then?
Just some thoughts,
CBODY67