I do not think "THE" harness problem is your problem. The starter circuit doesn't run through it although there may be a connection.

I would say it was much more likely that dirt or lack or lubrication kept the drive engaged. The only regular electrical problem I see that could cause this would be a sticking ignition switch helped by a big wad of keys. While the sticking could be intermittant the feel or lack of spring tention to the run position, should be noticable.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician