I too am unsure as to whether the idle problem could be related to the harness; however, I do know that the harness is in need of replacement. The MB indy made a 1" slit in the outer harness casing and he and I both looked at the interior wiring. The insulation on those interior wires was crumbling and cracked - not a good sign.
So, with that said, I am once again soliciting for help for the fast idle condition.
Thanks in advance,