W203 electrical gremlins

[219]

Before buying the 270 I had read that electrical problems were a feature of earlier cars , hence I had checked everything was working prior to buying .

The only problem I picked up on during the test drive was with the central locking 'machine gunning' when locking and the n/s/r door sometimes failing to lock . This , I was told would be a faulty actuator and would be fixed before I took delivery - all indeed seemed fine when I collected the car and the rear door now locks correctly .

I am now finding that the central locking actuator in the drivers door 'machine guns' for a second or so when locking the car , sometimes bouncing back to the unlocked position , sometimes needing two or three attempts to get the door to lock . This may be a matter of adjustment somewhere : I will have a look at the mechanism over the holidays . While I know that I could take the car back to the garage , they are a distance away and are just a general used car sales place , not Mercedes specialists , so I don't expect them to have in depth knowledge of these things .

The other issue tonight was when the display indicated that the left number plate lamp was out - on removing the lamp it was black , but replacing it with a new one made no difference ( tried both spare lamps I had with me and sure they are OK ) .

I also checked all the fuses in the rear compartment and made sure all the relays were seated properly . Will have a better look at things in daylight tomorrow .

Other than the above , the car has been reliable so far and a pleasure to drive .

 

[Druk]

Hi Derek.

I've replaced both front door locks on the 211 for just this very reason. Common fault as well apparently. Took one apart to see if it could be fixed and couldn't see anything wrong. Too fiddly by far.


.

 

[219]

We're the parts expensive ?

Just trying to figure whether to chase the garage to fix it ( and potentially be without the car for a few days ) ; or just to get the part and fix it myself .

It is only the drivers door doing this so I guess Id get away with replacing the one .

I might get one out of a 203 in a breakers ...

The number plate lamp started working again all by itself ???

 

[whitenemesis]

The bouncing locks can sometimes be fixed with a little lubrication trickled down the button stem. One common cause for bouncing is the actuator rod binding on a piece of insulation in the door. Or could be the spring gone/weak. These are replaceable as done by Alex Crow

Bouncing door locks on W203 and W211 - Mercedes-Benz Owners' Forums

 

[Benza750]

The door locks are around £80-90 ish + vat from the dealers, can be a bit fiderly to replace & side air bag will need removing from door aswell.
Usually around 1 - 1.5 hours labour.

When you replaced the bulb did you gave the lights switched on?
If so you have to switch them off then back on & simeted remove the key to reset the on board lamp warning system

 

[rf065]

I had the same problem with my number plate lights. Eventually had to replace one as the contacts in the light unit had corroded. Only about £9 from MB I think.

Russ

 

[219]

Thanks gents for the info , I had a look at the spring replacement guide over on the other forum .

I may have a look to see what a breaker might want for a lock mechanism , and practice taking another door apart before touching mine . I should be able to test a used lock by applying voltage before buying .

As for the lamp replacement , I did do it with the lights on . I also looked at the contacts since I have had corrosion in there on W126 and other models , but everything nice and clean ; I did pinch the contacts together to ensure good contact .

I had tried turning lights off and back on , as well as going into malfunction menu and holding the reset button - this cleared the warning from the display , but still showing 1 malfunction . although the light was still out ! When I went out in the car later , though , the light was working again and back to no malfunctions !

 

[rf065]

As for the lamp replacement , I did do it with the lights on . I also looked at the contacts since I have had corrosion in there on W126 and other models , but everything nice and clean ; I did pinch the contacts together to ensure good contact .

I should have said, the corrosion on mine was at the rear of the light unit where the wiring connects to the lamp unit. I had to remove the light completely to find the metal contacts had almost disappeared. Another bonus, on the CLK the rear boot lid is covered in plastic trim, after removing this all I saw was rust starting in quite a few places. Not sure if the estate has any plastic trim covering the paint?

Russ