the text from MBUSA simply indicates that there are no recall campaigns outstanding...

...doesn't appear to reference a wiring harness,,,and further- were wiring harnesses an official recall campaign?

in either case, (if you're serious about this purchase) a competent tech can do a comprehensive written report pre purchase inspection for you (PPI) and you can ask for the wiring harness inspection too...the PPI will save you $$$

-fad