While cleaning up some old wiring under the dash (W250) I found a set of four wires hanging They are coloured grey, black, orange and black. They seem to have some wires which are pluges into them which go nowhere. They are coiled up hanging on the E brake release. Also th econnection is done with seperate wires rater than a plug. Could it be an old brake contoler????

 

Fallow then to where they go , look at a wiring diagram .
On the plug thing you say both ways , have plugs then not ?
Sounds like someone added something , take a picture and show it .

 

Sounds like the trailer brake setup that comes with a towing package.
There should have been a blue wire though.