Thanks David. Good point about the stranded wire. Maybe I'll make a second version now that I've seen what's involved with doing this.

I actually did use the copper foil for patching up the flex circuit previous to this reworking. It works well, and I completely recommend it as a small fix if the rest of the sheet is in good shape. In addition to having been patched in that way, the layers on mine were separating, and I uh, sorta fried a couple of the circuits while tracing down a wiring fault in the turn signal circuit. Seemed like making a new harness was the best long-term option.

I am a bit concerned with the ground and main panel supply circuits. Everything seems to be working fine, but on a hot day, with the smaller gauge wire I used, I won't be surprised if I get some resistance in the circuit and it causes problems. We'll see how that goes. I figure, worst case scenario, I can always jump a second ground wire from the affected point to the ground pin in the connector if need be.

If I do remake the circuit, I think I'd be more comfortable taking liberties with the circuit map. Doing so would allow me to run a single heavier gauge main ground line which the individual circuits could tie in to. As it was, I started with the existing flex circuit sheet and cut out the most circuitous lines since I wasn't restricted the way it was.

The voltage regulator is connected to the original metal heat sink on the back of the tach, so I'm covered there.

Thanks for the feedback!

-Jarrett

On Dec 31, 2011, at 2:23 PM, David Beierl wrote:
> Use stranded wire for its better fatigue resistance.  The main panel supply and ground are 20-ga or so which might be preferable for those.  The panel lights get changed so seldom that I don't see any real problem soldering to them.  But to avoid that you could perhaps solder to that part of the existing flex-circuit if it isn't damaged.  Or craft supply places sell sticky copper foil for soldering pieced of stained glass together - of course a roll would be a thousand-year supply.