HaHa...a choke thing on your drivers seat...

? no idea what you mean ..take a photo and show us...
It hs been known sometimes when the choke cable snaps the quick way of fixing it is to shorten the cable and move the choke puller from the dash and mount it under the seat..which is maybe what you have


?
the winter/summer setting on your warm airflow valve is a valve that directs warm air from the manifold exhaust area to the air filter and into the carburettor ..it has a little leaver to change the airflow direction...set it to winter or your van will cough and splutter and even stop if ice forms in the carburettor