vacuum pump runs continuously on W140
 

The vacuum pump under the right rear passenger seat of my S320 runs every two to three seconds. will not turn off. It appears to operate the front lumbar supports. Does anyone have a clue as to what could be wrong? I don't want to burn out this pump!

gfdent

Leak in one of the lumbar bladders in one of the seats.
the lines under the carpets to the front seats can leak as well.
the pump is trying to pump up the seat, so dial the lumbar down
to (0). The pump will eventually sizzle if you don't fix the leak
or disconnect the pump.