This section of harness is about four inches from the AMM (air mass meter) in the center of the intake manifold. There was absolutely no indication from the outside. There are two outer layers, one almost a fiberglass like material and the other some of the toughest rubber I have ever seen. I had to use the sizzors to try and get inside without knocking all the insulation off.
Notice the darker, semi-green copper strands at the left and the brighter copper in the center. The brighter were uncovered in the disection process whereas the darker undoubtably had been that way.
Can you believe that this car had only irregular surging idle on first starting and mostly drove fine.
Bosch Master, ASE Master, L1
33 years MB technician