what circuit (s) went out? unless it has been majorly butchered you might clean every terminal/connection which will be WAY less work than installing a tailor made new harness and FOR SURE less work than rewiring from scratch like Charles said. I did a bare bones 65 Dart & it was alot of work, way more than I expected. I set the old harness on the floor and made a new one right next to it by adding 1 wire & cutting that counterpart off of the old harness till the new harness took shape and the old one dissappeared. You need to keep the OE colors including wires with tracers (stripes) and there are companies that will sell you specific lengths of any color & with or without tracers & I went to larger wires on some circuits & I crimped/soldered all new brass terminals & added some circuits. Me I would walk away and chill for a day or two then attack the specific problem. If you do go with a new harness find a recommended company which is what you asked for & hopefully an underhood harness will take care of things for you