280 SEL (126.023) vacuum heater/ac problems
 

Need help with identifying vacuum distribution block located on passenger side panel near console. There is a manifold with six solenoids and vacuum hoses. Would like to know what each one operates. My heater starts to blow cold air while the heater is on once the car is moving, maybe a door/flap is not operating correctly. The manifold is labled 1-6 with color coded circles. #1 red and white, #2 red and yellow, #3 red and blue, #4 green, #5 red, #6 green and blue, also there are two plastic globes (maybe check valves?). Any help in troubleshooting this problem would be appreciated as a manual is not available.
Thanks in advance!

From the top (at least on my 300SD) Best I could figure from the car and the CD.
1. defrost flap valve
2. footwell flap
3. center flap
4. diverter flap
5. fresh air/recirculating flap
6. fresh air/in car flap

Test each with you MightyVac and you'll probably find a bad vacuum pod.

If you have trouble maintaining cabin heat while moving or at high revs then check the monovalve if you have one thermostat control or the whatever the control valves are called on systems with left and right control valves. Maybe they're still called monovalves.

Do a search on monovalve and it should tell you what you need to know.

Sixto
91 300SE
87 300SDL
83 300SD