Central locking question

[Steve Riley]

Hi Peeps, me again.
My '91 190E has developed this thing where you click the button on the key fob remote and the indicators flash, the horn beeps but the doors don't lock.
The little stick things (techy stuff, huh?) on top of the door panels just quiver a bit but don't go down. When this happens, another press on the remote button unsets the alarm, then another press and it tries to lock again. Sometimes it takes 3 or 4 goes before it actually locks the doors. BTW, it only ever takes one click to UNlock the doors.
Any clues? Haynes on order but may take a week to get here.
Cheers,
Steve

 

[Steve_Perry]

Might there be a leak on the vacuum lines that drive the central locking? Any noises or hissing sounds?

The only other thing I can think of is the logic unit that governs the central locking might be on the way out.

I presume from your description that all four doors are affected.

Another test to try... try locking the door, the old-fashioned way with the key in the driver's door to see if it then works properly. It could be that the alarm unit has a fault or faulty wiring.

S.

 

[Steve Riley]

Hi Steve,
Using the key in the drivers door to lock the door only locks that door, same with unlocking. Still need to use the fob to turn the alarm on, which seems to work fine.
Steve (Mk2)

 

[Steve_Perry]

Umm shouldn't the key in the driver's door lock/unlock all doors & boot on the W201? May need a specialist and/or dealership to look at it. I'm out of ideas Steve, sorry.

To me, it sounds like it maybe the logic unit but I'm by no means an expert.

S.