I have read all the posts on the MAD alternator wiring upgrade from Marc Hamilton and I need a new alternator anyway so I decided to go for it. I havent been able to get a hold of Marc yet (always a busy signal) but I have unplugged the wiring harness block from the firewall and cleaned and separated all the wires. I have a good handle on everything except for a couple of "mystery wires". My question starts with the horn relay. One red wire goes to the harness block (assuming this is the dash power-up wire), another red wire goes to a 3-way splice between the battery, alternator, and external voltage regulator. I also have aone black wire and one pink wire going from the horn relay to the harness block. I checked Chiltons wiring diagrams and I can't even find a horn relay in the diagrams let alone a pink and a black wire coming from a horn relay. Does anyone know what these are for? I am wondering because the MAD upgrade suggests eliminating the horn relay and replacing it with a terminal block and I want to know what to do with these two wires. I apologize about the length. Thanks for any help!!