I got lucky the time I screwed up.

The drive shaft just rubbed a little bit of the insulation off, grounded it, and then set off the "Check Engine" light.

A little electrical tape and a heat shrink tube later and I was all set. I made sure I routed that wire and all others afterward very close to the car's body.

Live and learn!
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If it needs to be maintained, repaired or replaced on a 1990 240, I've probably done it. '90 240DL, 248K looking forward to 300K badge (or sticker??). >>You haven't really worked on a car until you draw blood<< :-}