I have the same problem with my 94 C-220 and have discussed it with my dealer. M.B. may or may not apply some credit for new harness and they only way to find out is to take your car to the dealer that normally services your car and ask for special consideration. They will contact M.B. and let you know but do not get your hope high for a car with 100K on it.

Do a search on this topic and you will find additional info.