Fog light wiring question

JB052

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On my recently purchased CLK (W209) the front near-side fog light does not have any wiring connecting it, just a bulb holder. All I can find is a broken (brown) earth wire behind the washer reservoir, there is no sign of the other (green wire) or the missing connection plug. Having spent most of yesterday looking for the missing wire I'm now considering alternatives.

My question is can I take a new feed from the green wire on the working off-side fog light ?
 

m80

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The fog light is often used when another light fails to compensate, so it is most likely to be left / right specific from the SAM.
I'm assuming yours doesn't have cornering lights, as clearly that's left / right, the same as above.
 
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JB052

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Just checked and I don't seem to have cornering lights. I'm not sure what the front SAM unit looks like or where its located on a W209.

However the main issue is that there is no electrical wiring to the near side fog light at all, so I presume it has been damaged and/or removed at some point.
 

m80

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The front SAM, there may be a rear SAM also, is often (but not always) situated in the under bonnet fuse enclosure, below the fuse board, if there is one there.

1st you need to know the colours you would be looking for as fed from the SAM. Then you have a chance of following that output to the point where it has been interrupted.
But I would be looking for a taped up repair on the loom, that assumes if / when the cable was cut back it was taped up to make safe.
If you can find such then testing the end of wire/s for 12 volt with the fog lights selected should be the answer.
 

Petrol Pete

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JB , you might have missed what m80 was tiring to explain was that on certain models the front fog lamps have different functions. They function as foglamps when asked to do so but will also illuminate if the headlamp on the corresponding side fails , some have a two filament bulb for this reason so just running a wire from one side to the other could cause more problems.
 

Ted

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Iirc the fog lights on the a209 are fed separately from the front Sam. This means that the current is electronically limited and you can’t just tap in to the other one.
the Sam is the fuse box right next to the bulkhead on the offside.
 
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JB052

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Thanks for the updates guys, following your advice I will continue my search for the elusive missing green wire, rather than take a feed from the other fog lamp.
I hadn't fully appreciated that the fog lamps may compensate for other light failures.
 

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