I had two like new parts car wiring harnesses from two 1968 road runners and I debated about buying a reproduction '69 harness so I printed both the '68 and '69 wiring schematics from here: http://www.mymopar.com/index.php?pid=27 and http://www.mymopar.com/index.php?pid=18 and then tracked/traced EVERY wire on both the '68 and '69 schematics and learned a lot about the where and why and also the one small difference between the two. I'd start at a switch or point on the dash and work toward the firewall junction and the fuse box and then to the alternator, relay, and battery. That's how I found the yellow with black tracer missing on the '69.....because it doesn't have four side marker lights just side reflectors. I think engineering wise they turned the front parking lights off to minimize the demand for running the headlights along with the four side marker lights on the '68. Maybe the current demand for running the high and low four headlights, four side maker lights and two more front parking lights was deemed too much for the wiring system???

My first car in '69 was a brand new '69 road runner and I always remembered the parking lights being on with the headlights. When I got the '68 road runner I thought there was a problem with the wiring when the parking lights would go out when I turned on the headlights then I was told they go off on the '68's when the headlights went on.....and then it hit me with the side marker lights Oh it's been lots of fun learning even as I get older