Mercedes ML Trip Computer B26 compass module
 

I recently purchased some Mercedes Trip Computer Modules Mercedes A163 540 52 11 they were individually baged in a boxes of ten and we have had luck installing them on ML 320 and 350 models that didn't come with the trip computer, by unplugging the 8 pin connector on the overhead tow away module and plugging it in. The palstic fascia panel has no hle for the LCD screen , so a square hole has to be made in the right location.
The Problem I have is that there is no compass function on the unit . Two of the wires on the 8 pin connection are suposed to go to a B26 Remote Magnetic compass module that acording to wolfgangs web page is located "under the plastic edge rear of the loading area"
The problem I have is that I need the part number and price for the magnetic compass module, so I could test one of these units for it's compass function.
I was told by one person that they thought It may require a reprograming by the dealership to fix the compass function, but since everything else works. I'm hopeing that the module is all I need. There is more info on ebay " trip computer"