wiring harness replacement | Triumph TR6 | MG-Cars Triumph TR6 - wiring harness replacement. I'm starting to pull together my list of winter project, among which I plan to replace my top dash and possibly refinish my dash. I also have lots of little electrical imperfections, so I'm also thinking the easiest fix is simply to replace my entire wiring harness while I have my dash torn down. I Wiring Harness Conversion or Replacement? - triumphexp Sep 12, 2012The existing wiring harness hasn't exhibited any major issues, but while I have the car apart, it is much easier to do replacements or upgrades now. I've seen several posts on the Advance Auto Wire product, but it appears to be a BIG job having to cut, solder ends, etc. versus buying front & rear replacement harnesses from TRF or Moss Motors.