The pre-1996 cars used a biodegradable insulation that cracks and crumbles, taking out engine and injector wiring and even reaching into the throttle actuators. Commenters agree the updated harness fixes it permanently and is a relatively cheap part, though labor and the shrinking supply worry buyers. …
Biodegradable wiring harness on the early (1992-1995) cars
Mercedes-Benz S-Class Coupe / CL (C140) · mechanical