(Please move if not categorized properly)

In my 1999 mini, I have dual zone climate control. The passenger side goes from hot to cool, but the drivers side has issues doing so. Sometimes it will go to the extreme hot or cold as expected, but only after 10-15 minutes driving. Usually it never gets to hot or cold.

I tried calibrating by holding in two buttons and allowing the system to run through all its motions, but that didn't completely solve the problem.

I think each climate zone has a hot/cool servo that operates a flapper. I'll assume that the drivers side is hanging up or the linkage is broken.

Can anyone walk me through accessing, diagnosing, and repairing this? Or if you have a FSM scan or link to the repair.

Planning a family road trip later this month and AC would be very nice to have!!

Thanks!!