Once you do a search for wiring harness posts, you will discover that most people say to open up a section of harness, and examine the wires closely. If you spot insulation that is cracked or worse, you will need to replace the harness. As a matter of fact, you will need to replace it yesterday, before it damages any components. Also, if the harness has the defective insulation, you will also want to seriously consider coming to grips with the fact that you will probably have to replace the ETA as well.
Shop around - Phil can get you a good price on a harness.
ETA= Electronic Throttle Actuator (aka throttle body)
Don't bother telling Benz that this is a safety issue and ought the be covered under some sort of recall - they will tell you they know nothing about it.
