Locks

[drewmwillis]

Hey All,
How are the locks supposed to work in theory on my 1991 500SL?

As of right now, I have to key into both doors sepeartely, and the keyless entry button just turns on and off the alarm -- I'd hope the keyless part is supposed to lock and unlock the doors.

Thanks in advance!
~drew

[TheV12pwr]

You must have a faulty pessure/vacuum pump located in trunk above the battery,if all the fuses check OK.

[tecqboy]

Check the fittings at the vacuum distribution manifold as well. You can use a hand vacuum pump to check out each vacuum circuit. The vacuum circuits lock the rear storage compartments and the glove boxes as well as the doors. The pump should run when you lock the doors with the manual lever on the inside of the door too. The rubber hoses get old and brittle and often just plain crack. There are a few check valves involved too. With a little detective work you should be able to fix this problem without much hassle.