W211 reverse sensor wiring help

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1975andyt

New Member
Joined
Nov 10, 2013
Messages
18
Car
Mercedes E270 cdi
I've retrofitted some reverse sensors to my 2003 E270cdi and an struggling with which wires to connect to +ve and -ve to, I've tested the sensors and buzzer on a battery and it works fine, it's just which colours to connect to I'm struggling with, I can't seem to get 12v on my meter, any assistance would be appreciated.
 
I would be interested in knowing more about how you have done this and what parts you bought to do the retro fit. I have been thinking about getting a kit for mine, as its the first car I have had in years that has not had them fitted as standard.

Thanks
Marcel-Anthony
 
Can someone expand on M - A please? Cheers, Andrew.
 
Hi Ted,

Could I ask you to expand a little on this please Ted.

I fitted some cheap wireless ones from E-Bay. These have worked perfectly for me, although many people don't like them and recommend the 'Steelmate' brand.
In my case both the sensors and to a slightly lesser extent the display look pretty OEM, with the advantage that as well as the LEDs there is a very accurate distance display.

There is no need to remove the rear bumper - you can feel up behind and there is plenty of easy access. There is also a hole below the offside light cluster. Push a wire through from inside the car, locate it, tape the sensor wires and pull through to just in front of the cluster. Splice the control box into the reverse light wire (use a testlight) and earth (brown wire) and the box fits neatly to the panel just below the rear light and is covered by the boot trim - totally invisible.
That's the sensors fitted - around 45 minutes.

The display goes exactly where the oem display goes - just in front of the front centre vent. The vire to the display is hidden in a channel just under the windscreen - just push it in, and bring it round the nearside, under the glovebox, and plug into the fag lighter to test. I left it like this for a week, and then spliced it into the fag lighter wiring.
Around another 45 minutes to do this.

I can post some piccies over the weekend if you like.

Edit:
This is the display in my car
36710d1369940185-tae-hell-wi-poverty-image-183264069.jpg
 
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Thanks for the info Ted, its appreciated. Last night I put the car into reverse so the reverse bulb was light and then unplugged the multi wire connector and the light went out, I then put my test meter on to earth and on to each of the wires and none of them gave me 12 volts, I tried a different earth and checked the meter against a battery. I don't suppose you can remember which colour wire you spliced into? I'm baffled as to why I can't get 12V.......aaaarrrrgggghhh!
 
It's the rear SAM detecting that you have unplugged the bulb. It then pulses to check.
Plug the connector back in and test it again :)

Edit: can't remember the reverse colour (can find out tonight if it stops raining) but I would expect O/S rear sidelight to be grey/red, O/S indicator to be blac/green or black/white - can't remember which, and brake to be black/red. Earth is of course brown so reverse will be the other one :)
 
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As Ted says, make sure the connector is plugged in and use your meter to find the reverse light. Your meter probe will fit into the holes on the back of the connector block.
I did this job on my Mum's 211 over the Easter hols. I ran the sensor cables through the gromit on the near side.
From memory, I think the reverse light cable is grey with yellow, but I could be wrong. I believe it was the second wire in (starting from the near side).
But use your meter to confirm.
 
I fitted some cheap wireless ones from E-Bay. These have worked perfectly for me, although many people don't like them and recommend the 'Steelmate' brand.
In my case both the sensors and to a slightly lesser extent the display look pretty OEM, with the advantage that as well as the LEDs there is a very accurate distance display.

There is no need to remove the rear bumper - you can feel up behind and there is plenty of easy access. There is also a hole below the offside light cluster. Push a wire through from inside the car, locate it, tape the sensor wires and pull through to just in front of the cluster. Splice the control box into the reverse light wire (use a testlight) and earth (brown wire) and the box fits neatly to the panel just below the rear light and is covered by the boot trim - totally invisible.
That's the sensors fitted - around 45 minutes.

The display goes exactly where the oem display goes - just in front of the front centre vent. The vire to the display is hidden in a channel just under the windscreen - just push it in, and bring it round the nearside, under the glovebox, and plug into the fag lighter to test. I left it like this for a week, and then spliced it into the fag lighter wiring.
Around another 45 minutes to do this.

I can post some piccies over the weekend if you like.

Edit:
This is the display in my car
36710d1369940185-tae-hell-wi-poverty-image-183264069.jpg


Looks great, but more pics of the sensors in place would be good if you get the time, no rush.

Thanks
Marcel-Anthony
 
View attachment 42701

A rather wet photo.
I only installed two - you get four in the set. I now wish I had put them further out with two in the middle, as there is a small dead spot in the centre, but I was unsure just how far out I could go.
Colour match was excellent.
 
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My sensors are now connected and working fine, many thanks for the advice
 

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