I own two W140's 96 S320 and 98 S500.

My understanding is all the W140's of a 1995 and below manufacture date which is a "1996 car". Had the issue of the harness. My 96 only had the issue with the harness in the mirror area. My 98, no issues at all. All the "Drive by wire" cars do not have this issue which are 96-99 V8 & V12, and 97-99 S320

Their are many cars in the junk yards with the updated harness' on them. The updated harness' have the words" Delphi" on a label on the harness. It takes about 1/2 day to a day to change out a harness. The V12 will cost you more effort because everything is just tight..

Their is a Mercedes test procedure to rule the harness as the culprit if the obvious of cracked insulation is not seen.

The V12 harness is $2k at dealer wholesale pricing.

Remember you got to pay to play Mercedes. Just because the car was purchased at $1k. The part prices are 2013 prices.

Martin