air flow wrong vents?
 

Push the button for economy and air flow is out of the front vents, as it should be. Push the button to the immediate left, allegedly the same air flow pattern, with air conditioning now on and flow is out of the side vent and defrost vents only. Zero flow from the front vents where it should be flowing from. I replaced the push button controller and the vacuum bar with brand new parts same thing? Curiously in the early morning or at night occasionally the flow will come from the correct vents. Hottest part of the day, defrost only. Anyone have any idea on how to correct this? '87 560SEL similary afflicted!


87 560SEL 135,000
86 300SDL 165,000

I think the main difference between those settings aside from the compressor is that in A/C at least one stage of the recirc door is closed. I would suspect a leak in that stage. It is a dual unit (two separate two stage units). I would replace both.