W124 Central Lock Puzzle
 

My 1987 300D Central Locking did not work so I replaced the supply pump. Now, all the doors lock and unlock from the passenger side, but not from the driver side or the trunk. I replaced the left front door actuator and trunk lid actuator and still the same problem.

Any ideas what to try next?


'87 300d
'01 CLK 430 Cabriolet

Are you trying to lock the door manually or with the key?

I tried locking the drivers side door with the key and manually when the door is closed and no luck. The same was true when I tried the trunk lid.

The system works when I lock the passenger side door manually or with the key.

I finally fixed the problem. I had to use the wiring diagram and had to pull back the rear right side carpet to find the X48F connector. It apparently corroded and only 2 of the 4 wires had any contact for power. I resoldered the connection and 2 additional ground connections in that area that were also corroded and everthing works perfectly!

darn corroding wires :)

had a simlar story with windshield washer fluid pump he he :)

xp

DJANKOV
 

pLEASE SIR, can you show the wiring diagrams with the location of the X48F connector?

Thanks

Mario Farias

hello,

congratulation for fixing at very lost cost this problem.
I believe that with our nice little old cars we are facing similar inconvenieces.

Someone for another topics has put photos, which I find is very good idea.

Could you join photos as well of the connector?

Sorry, I didn't take any photos. However, the X48F connector is actually a simple connection of the power and ground to the 3 actuators (left door, right door, and trunk) and the central locking pump.
To get to it, you need to remove the back seat and peel back the carpet in the right rear foot area. The wiring harness is located in a plastic U shaped channel with a snap on cover. You need to un-snap this cover and unravel the harness insulation. You will eventually find these connectors located in the somewhere in the middle. When I found mine, they were transparent in color with green corrosion inside. The corrosion was so bad, that I could pull apart the wires easily.


1987 300D 185Km
2001 CLK 430 Convertible 27Km

Thats great news!!
 

Wow thats great information. I am almost tempted to sneak home at lunch hour to take a look! I will post a picture when I get to it!!!

Thanks!!!!!

Location of the X48F in rear wiring harness?
 

I pulled the carpet up and I had to unbolt the seat belt and take off the door pillar trim.
I could only get access to about 7 inches of the harness in the plastic trough. To get more access I might have to take out the drivers seat!
How far forward from either the pump or the rear seat edge ( ie the hump) is the X48 connector?
I dont think I will do this in 15 degree weather again--plastic snaps and cracks easily!!!

Location of the X48 in rear wiring harness?

Respectfully
Carrameow

I had a windshield washer pump that corroded away on one side...the connection was good but the pump was dissapearing fast :)

I believe the connector is located about 10 inches from the rear seat edge (or about 15 inches from the pump). I had to pry the carpet up with a stick to hold it while I located the wires. This was at 65 F, not 15 F. I can imagine how challenging it must be in the cold temperature.
I didn't have to remove the passenger seat, but I moved it as far as it would go forward to get access (you mentioned driver's seat?)
You have to unwrap the black tape to get to the wires.
Good Luck!

You Were Right!
 

Right where you said it was, the red white splice was corroded and th eground splice was corroded. The SYSTEM NOW WORKS!

THANKS!

Awesome, 5 years later , this still works :) . The X84 connection is just a crimped on connection with 5 wires, maybe 6. Mine was just a few inches from the seat edge where the wires go in under the seat to the pump. Some wires will just break in there after many years. I guess the tape is not all that moisture resistant. I wrapped it back up with regular electric tape once finished. This makes the middle dome lights work too as they get their power from that. Sweeeeet. Thanks mercedes shop.

I believe I did a posting on the same subject years ago (with pictures).

Do a search for "Help me find this positive voltage distribution point"

It will probably show up....