Wiring Harness

I took my '95 C280 to my local dealer last week and showed him the cracks in the insulation at the intake air temperature sensor and the engine coolant temperature sensor. They removed the cover and looked at the harness where it runs along the top of the engine near the injectors, etc. I told them that I have heard that there have been problems with the M104 engine harness and their reply was that they didn't see a problem with mine, other than normal aging and mileage (85000). I asked if they could check with the factory rep and verify if there was or was not a history of problems. They said that they would. The service manager called the next afternoon and said that neither the factory nor any of the technicians had ever seen or heard of a problem with these harnesses and that they would, of course, be happy to repair or replace it at my expense. Let it be said that they treated me extremely well. And since the service manager is a freind of a freind, I wasn't even charged for the evaluation. So, I'm not in a position to push the issue or make waves. Any suggestions out there? How much does the harness cost?