'92 E300 diesel Rear Headrest problem
 

heres one for you.

checking out the rear headrest control. there is voltage from the console switch and to the connecter under the rear seats that joins to the vacume lines when the switch is pressed. but there is no vacume. yes the engine is running. but after i have checked the white pipe that runs into the little box that splits the pipe into 2 white with blue stripe. placing my finger over the other white pipe it contains no suction.

where does this white pipe run to? as i need to trace it to see if there is a fault there. just to add it is not an electrical problem as there is voltage present. and the vacume control over the other side does not have a white pipe running from it. only 6 yellows. which are for central locking.

help please:confused: