Unfortunately, the manual a/c system also contained a heater control valve also made of Bakelite that also cracked every two years at best as well. Both systems were badly flawed as a result. When the cracks formed (not "if") about every two years, the valves would start leaking as you were driving and the loss of coolant as you drove would cause the cars to overheat since most Chrysler models in particular only had a warning light to tell the driver that the car was overheated. So there was no gauge to warn one of impending trouble, just an "idiot" light. The word "idiot" was for the engineer that thought they would be a hero to cut the cost of the previous heater valves by using low grade plastic instead. I wonder how many sales were lost due to both "thrifted" systems - just dumb.
And all the Chrysler Corporation radiators in the early 70s and beyond were marginal in terms of keeping the cars cool in hot climates such as in the Southwest because radiator materials costs' were high and Chrysler thrifted those too as a result. I saw the proving ground data when I was there and it showed GM and Ford both had much better cooling margins than Chrysler did.
All the cost cutting I was seeing in the 70s led to Chrysler's bankruptcy circa 1980 (combined with Lean Burn engines), after which Lee Iacocca took over and righted the ship to some degree.
