Any ideas what a universal harness would look like? Would it be home run wires from the fuse box to the devices or would there be some connector plugs in between. If it comes thru the firewall in a round bundle, just cut out two rectangular pieces of thick rubber a little larger than the orininal harness port and route the new harness thru the rubber blanks with a hole cut to except them. The rubber can be either cut to friction fit into the hole or if made larger enough, glued or screwed to the firewall. I have never done this as I used three original harnesses to restore my existing but with a little creativity you can come up with something you like. Sometimes when you hear ideas that sound dumb it makes you think of what you really want to do by thinking about what is wrong with someone elses idea!