[CE9311]

You have a very common issues, heat from the side vents is usually caused by a vacuum leak somewhere in the HVAC system. It's usually either the rubber connectors or the pods that go bad. If you do a forum search, I know we've got some writeup threads on how to fix the issue.

I think you need to research bit more on the HVAC system in the LX / LD bodies. None of the controls or doors use engine vacuum to operate. Not to mentined notice you replied to a 4 month old post where OP will most likely never return seeing they too haven't been back in 4 months.