I would assume you run one line from the pump up to where the seats are, and T is off from there. As I understand it the pump just makes a constant pressure (and shuts off when that pressure is reached) and the dials set the pressure going to the balloons in the seats. I may be wrong tho. I'd give the service manual a read

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.