more monovalve questions

[sclassforever]

I couldnt find much info in the archives on monovalves for later 93 W140 S-class (400SEL)
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Im wondering how I can isolate this as the problem.
I have no heat.
I read something about a guy pinching the heater hoses off, but I tried that and still got no heat. Is that how you determine its the monovalve? there are 3 hoses going into one half and one into the other part, it looks like a two stage monovalve.
I wasnt sure how long to keep it pinched off before heat would come out.
I guess i dont want to buy a $453 dollar part if im not sure it will fix my problem. Could it be a door or flap is not opening? is there a way to isolate the valve as the problem? I pinched all 4 hoses and still had no heat, but only for a few seconds each.
How does the climate control buttons open the doors and flaps with microservos? I hate this, winter is coming soon here, and I cant afford $1000 to just fix my heater. Is there a cheap jerry rig fix? I dont care anymore.