Cant lock or unlock drivers side door access from boot only

[probids]

I have a 1990 SL500 Mercedes (R129) the problem I have is that I have to unlock the boot to get in the car and again to lock the car up. The green and red lights in the door are working and I was wondering if I can get a remote to work with these. When I put the key in the driver’s side it just does nothing will not unlock or lock.

Funnily enough I just had a similar issue with W126 300 SEL but we changed the passenger and drivers locks over as it has central locking.

Any help would be appreciated

[John Green]

Hello probids, first up you have a 500SL not a SL500.. The change was in 1993. Sounds very pedantic to point that out I know, but wait until you get sent the wrong parts after telling the parts guy it is a SL500...

Anyway onto the problem. You mention the key not working in the drivers door, but what about the remote pointed at it? I presume not? the first thing I would look at is the mechanical link from the internals of the door lock to the central locking element. Presuming that is OK, I would then see if the electrical switch inside it is working, test this with a multimeter, from there you just need to keep following the fault to the pump, which we know works.

Another possible fault could be the wiring where it goes though to the door, if it is a high mileage or losts of short trips example, the door has been opened a billion times and can damage the wires.