Door lock system is not working at all.

- Is it a vacuum system that operations the lock system or is it electrically. Driver side will not come up at all using the door key.

my drivers side will not come up using the key either, when I opened up the door panel i found that the part of the lock assembly which connects the key part to the lock part was broken. Now I just use the trunk to lock the car.

The driver's door and the trunk are not vacuum dependent.

"The driver's door and the trunk are not vacuum dependent"

I don't know what this means, but the driver's door, trunk and all other doors including gas filler all have 'vacuum' actuators. The front doors and trunk also have switches incorporated to trigger the pump. The trunk lock can also be turned to a position where its actuator won't unlock it. The pump itself is pressure/vacuum, depending on trigger polarity, with built-in flow/pressure switch, so there is only one pneumatic line to each actuator.

Steve

The response was meant to indicate that you can open the driver's door and the trunk with just the key. The vacuum system doesn't come into play with these mechanical systems. Imagine not being able to get into your car or trunk because the battery was dead. If you can't lift the driver's door with just the key, you have a lock problem, in addition to possible vacuum problems.

The locks on my '88 190E 2.6 are electric solenoid actuated. You can tell by the sound and lack of vacuum plumbing. I believe some older Merc models might use a vacuum system.

You should be able to lock and unlock both front doors manually. (I know mine will when the battery is disconnected.) If not there is probably a linkage problem inside the door.

Duke

"The locks on my '88 190E 2.6 are electric solenoid actuated. You can tell by the sound and lack of vacuum plumbing. I believe some older Merc models might use a vacuum system."

Duke, according to FastLane, yours uses essentially the same parts as our '91 - all vacuum. Has yours been converted?

Steve

Sorry, I screwed up. Looking at my Model Year 1984 manual I see that the 201 central locking system is a vacuum/pressure system that has it's own pump. That's the "electrical noise" I hear when locking and unlocking the car.

Duke