Went on a little trip, and noticed that after a couple of hours on the road running the AC, the comb flap (I think) would close, preventing strong airflow from the center vent.

Verified this was not due to a vacuum issue; I already fixed that problem.

It appeared to be due to the system thinking, perhaps falsely, that the interior had reached a target temperature. The only way I could get the comb flap to reopen was by turning on the rear AC. That worked every time. This seems like odd behavior to me.

 

Min temp override (e.g. temp slider all the way to the left) should get you comb flap to heater core bypass always. If it doesn't - you have a problem.

Alan

 

Yeah, it seems like temp slider full left has never done anything for me.

 

There is a Micro switch that it needs to hit when in the left most position, maybe it isn't depressing it?
Sometimes you can hear it click, any slop in the lever it may not work.

Dave K

 

I have never heard a thing at full left; I suspect the switch is either broken or not getting depressed. Have been in this condition for 6 years.