If you have access to both leads. I bought a simple 2240:60 speedometer with a neutral, high beam, and turn signal indicator integrated that has a single negative lead for all lighting. This guage is looking for a positive on neutral whicb my clumbsy solution provides.
Ok if it works for you guess that is fine. but in my logical mind. I can't see any issues to solve.
because, if you are not using the stock clockset you will still have the plug ends on the main harness that went to it, all the positive and negative wires you need are right there in those plugs (which BTW are standard configuration plugs available at most auto suppliers) just feed those wires to the new clock job done.
the other puzzling thing to me is why use a standard 4TR (4 terminal relay) and override the relay by joining both power wires to the same source, (keeping the relay energised) it's not what a relay is designed for. one positive wire direct to the bulb would have worked just fine.
I don't have a US diagram handy but on (UK) models the bulb wiring is.
1. clock illumination in, red/blue, out black and yellow.
2. indicators left green in black/yellow out, right grey in black/yellow out.
3. main beam red/black in black/yellow out
4. oil light brown in blue/red out
5. neutral switch brown in light green out.
all those wires are there in the plug ends, the majority of the bulbs are power in earth out but the oil light and neutral light are power in and respective power out to the switches. the best wiring solutions are always the simplest.