Rallye cluster gauge issues - 67 Barracuda

PS. On my 67 Barracuda there was a ground wire from the capacitor mounting to the radio brace. It looks original but even if not, not a bad way to do it.

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PSS.
Since Accessory also powers radio, turn signals, wipers, and heater fan, checking those will help isolate a loose or poor connection if that's the problem.
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