CJG1973

Hello all - short term lurker, new member, first post (and all that stuff...) I lucked into a 1973 620 (Built 1/73) stashed in a barn for the last 27 years with 47,000 miles. (and I think those are correct, based on the lack of seat tears and how clean the pedals are). I've got plenty to do to it, but I'm trying to understand the dimmer switch. I've searched through multiple posts on the 620s and the overall electrical system. When I bought the truck, it was missing the dimmer switch and I keep seeing references to an "optical wire" for the dash lights. Now, I've got to handle some floorboard issues, plenty of tune up stuff, and cleaning out the fuel system, but I'd like to learn how - and what - the dimmer switch system works, what my options are for dashlights (of any brightness) and what you guys think would be the smartest move as far as making sure my electrical system is worry-free. My overall goal for the truck is to make it as reliable as the B210 I had eons ago - and when my son is home on leave from the Corps, he can use it, too. Poking around under the dash, I did find what appears to be the "optical wire" broken in multiple places. I actually haven't even put a battery in this one yet, but I'd like to begin to get a plan together. Selfishly, I don't want to burn this one up. 90% of the harness looks good. Oh, and is there a cheat-sheet in the forums for wiring diagrams and/or a list of where all the grounds for this truck are located? I know how bad resistance from bad grounds can be for reliability. Thanks everyone... Chris