freezing my beejeezies off, need help with 560SEL w126

[randallk]

I recently purchased a 1987 560SEL.
I was not getting any heat and replaced the mono-valve. The temp gauge only read 60° c
And I replaced the thermostat. After replacing these two parts I had slightly warm air out of defrost and floor vents, nothing from the center vents. When switching from defrost to other controls on the control panel it takes a good 30 seconds for it to switch to the correct vents.
After driving it for 3 miles I no longer have warm air, it only blows cold air from the defrost.
can anyone direct me what to do next?
Does anyone know where I can get a schematic
Of the HVAC system and operation manual?
Thanks