The gauges are Dolphin, and I do have the wiring diagram which all looks right.

As for a diode or capacitor it it doesn't say anything about it.

Charging system is fine.

And the wire for the light is correct.

I was looking at a wiring diagram and it mentioned that with an MSD ignition that you need a tach filter, but the tech at MSD said he didn't think that was the problem nor was it needed.

Rocky