The early model contours were notorious for wiring harness problems, but I didn't think the 99's had that much of a problem. As far as the cost to replace a wiring harness.......don't even ask.....sorry... There are several harnesses under the hood, so the cost will depend on which one or ones are defective. You're probable looking at several hundred $$$ at least, if you replace with new ones. I would consider all options before I had a mechanic do a wiring replacement.
