I've read some of the previous threads on this subject, and still have questions, so I apologize for re-covering ground, but...
PO installed ball valves in heater in and out lines, so I assume the vertical temp control wheel in the console is inoperative.
With both valves fully open, Def button pushed, Iget too much heat!
With both valves set about half, temp is toasty...
Def pressed, I get full fan, lots of hot air from windshield Def vents and outer dash eyeball vents, nothing from centers.
If I then select BiLev, Auto Hi or Auto Lo, I still get warm air from outer and windshield vents, no fan(or very low).
If I select any of the above from Off, without first using Def, I get nothing.
I never get any heat from lower or floor vents, and sometimes seem to get cold(very cold, lately) air coming from console/floor area.
A/C seems to work--Blows cold when switched on, windshield and outer vents, no centers, no lowers, etc.
Please, please, please show me the way
. Thanks, Glassman