[shopcarpro]

By the way -
do you know how to get to the "0-5" switch to check/clean it (if can be cleaned at all)?
On the driver side it feels like not responding till in "0-4" position and then towards 5 it inflates very well.
Probably there is a way to remove this plastic side cover.
(W140 1991)

Take the Side cover of the seat which holds the adjuster switch off. Then from inside of the seat cover the switch can be taken out n cleaned. Be careful not to brake the two tabs in front of the seat cover.