Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, the door lock issue is a common problem with it bouncing up & down & is a fault with the door lock itself. The door lock will need to be replaced to cure this problem. The door lock is around £100 for the part with around 2 1/2 hours labour to replace.
With regards XXXXX XXXXX warning for the no. plate lamp - if the light is working then it may be a bad connection or the bulb has gone black - check & clean the contacts or replace the bulb as required
Best regards, Paul
the other problem is when driving and you go over a bump in the road there sounds like something rattaling/knocking under neath what could this be as ive replaced both arms on both sides as the bushes and ball joints had gone
Hi - the most common problem for knocking over bumps it the anti roll bar links - check to see if there is any movement on the joints on the ends of the links - even the slightest movement will cause noises & if movement is found then replace the links
it sounds like its coming from the front but cant be 100% sure
yes - the front anti roll bar links are most common
if not the anti rollbar links what else could it be it almost sound like its vibrating
hi - just eating dinner at the moment! sorry for any delay!
ok i will check these parts tomorrow and if they sort the problems out will pay £28. Im sure they will but first time ive used this service. Is that ok as im not sure how this site works. Thank you Mr Sterry
If it is more of a vibration then I would check all exhaust mounts & brackets as they can fracture or break
that was the first thing i checked
hi - ok, I would still suspect the links from how you described it!
Let me know how you get on tomorrow
if it does sort the problem how do i pay
Hi - if you are happy with my answer then just click "accept" or let me know if you need anything else.
so i can just sing in to my account tomorrow and accept is that correct ???
hi - yes, correct - just come back to this question & click accept or let me know if you need anything else.
Thank you speek to you tomorrow Mr sterry
Hi - I hope all goes well! Paul
hi there sorry for not getting back but weather has been bad and not had the chance to do much till today but the door lock is fixed and the anti roll bar links replaced and all is now fine no knocking anymore but still have the check number plate lamp L have checked and changed bulbs in both lamps and cleaned connections but warning still on dash can you please help as i still owe you £28 pound for this question
and this also only comes on when it starts to get dark if you put lights on in the daylight the warning doesnt come on the dash
Hi, glad you have got the other parts fixed now
with regards XXXXX XXXXX number plate lamp, if the bulb is good then it will need some testing with a multi meter or test lamp - the boot linings will need to be removed & the rear fusebox taken out to test if there is power coming out to the lamp
often it can be a fault within the rear SAM unit which supplies the power to the lamps
If you would like help testing this then please let me know your VIN number so I can check the wiring diagrams, otherwise it may be a job for a garage or auto electrician
hi there thanks for getting back if you could give me help testing it it would be very helpful the vin nuber is wdb2037062a423110 hope this helps
hi there did you get the vin num paul ???
Hi, ok - pin 1 on the back of the number plate lamp is an earth - check for for good continuity to earth here. Pin 2 is the 12v feed from the rear SAM unit - check here for voltage with a test lamp (just by using a volt meter will not always be enough for the SAM to output a voltage). once connected turn the ignition & lights off - then switch back on to see if the test lamp comes on.
If there is no voltage to the test lamp then you will need to check the wire back to the rear SAM - this is part of the rear fusebox in the left of the boot - remove all trims & loosen the rear fusebox
The left number plate lamp is fed from pin 25 in block number 21 in the rear of the SAM unit
Check for continuity down the wire at this pin to pin 2 at the lamp itself.
check with the test lamp at this pin directly at the rear of the SAM
If all the wiring is good & there is no power to light the test lamp then it is likely to be a SAM fault
hi there there is power to the lamp as it works fine but warning is still on dash
Hi - ok, have you checked what voltage you are seeing & if there is good continuity down the earth line?
hi i will get a meter in the morning and check ? what readings am i looking for in voltage and i presume 0 in the earth yes/no
what time are you on line tomorrow
Hi - you should be seeing battery voltage down the supply & minimal resistance down the earth wire
Let me know what readings you see
I will be around most of tomorrow
hi there thanks for getting back the readings are at the lamp supply 12.13 earth 0 left light and 12.14 and 0 on the right light at the back of the rear fuse box the supply is 12.34 and 12.32 but not sure of which pin is earth and where is wire earthed to the body as have taken readings from the earth insid the left side of boot on inside of the rear wing and this is 0 have i done this right i am using the gunson automotive multi-meter from halfords for £54.99 also when i check for earth what prob do i conect to what i am conecting the black to the rear boot catch and the red to the earth on the body is this corect thank you mr sterry
Hi Mr Sterry - for checking the earth you need to set your meter to resistance ( Ω ). connect one lead from you meter to the earth pin on the lamp & connect the other to any good earth point on the vehicle. You should be seeing less than 1Ω resistance ideally. The boot catch is usually fine. This is checking the earth wire from the lamp back down to earth on the vehicle body
Let me know what you find
hi paul the readings ive taken are from 3 different settings the first is (200) they were 06.4 left light 08.4 right light 00.5 where the earth bolts to the rear inner wing . setting 2k .182 left .187 right and earth to inner wing . setting 20k 0.32 left 0.33 right and 0.01 earth to inner wing hope these readings are what you need thanks mr sterry
Hi - the readings seem a little high - though it may just be a poor connection through the body - I would try cleaning the earth connector on the rear inner wing to see if this helps - otherwise I would check the connectors to the rear of the SAM.
hi paul thanks im now going to clean the earth on the inner wing and check connectors at back of sam will email back very soon
Hi - no problem, I will look out for your reply.
Just to let you know from this afternoon I will be away on a meeting for a couple of days so may not be able to reply until I return
hi there paul i ive found where the problem is coming from ,theres a wire coming from the right number plate light live to the left light that someone has done befor because there is no power to the left live. So can you help me test the sam unit please thank you mr sterry
hi paul just checked sam unit and it has no power coming from pin 25 so must be sam unit can you tell me are they coaded or can i get one from scrap yard ??? thank you mr sterry
Hi, they are coded for certain items (fuel tank sensors from memory) - they are a fairly common problem for various complaints so would always recommend a new unit - they are around £200 from memory
sorry about the delay in replying - as said I was away & have only just been able to catch up!
Please remember to click "accept"
hi there ive got a new sam unit and fitted it to day but every thing seems to be working fine do i need to take it to mercedes for it to be coaded or will it be fine i brought it from mercedes ??? thank you mr sterry
Hi - the only thing I can think of is the fuel tank sensors need coding - there are 2 types & they default to one type - if the fuel gauge is reading correctly then there is probably no need for coding
If the gauge is reading incorrectly since replacing the SAM then the coding for the sensors will need to be changed for the other type
there is a 50/50 chance that it is the right type!
hi paul thank you very much for all your help if i need any further help will contact you thanks once again mr sterry