The ammeter is a part of the battery power feed. There are two different colors used so the ammeter reads correctly.
When the wires are connected, black is hot, just like the red is hot.
The black wire is connected to the MAIN JUNCTION. This is a WELDED SPLICE.
Everything connected to the welded splice is hot.
The splice joins the two power sources, battery and alternator, with the dircuits that feed everything else.
When the key is off, half of the fuses are off.
With the key off, there should still be power at the fuses for the dome light, brake lights, tailights. There should also be power for the headlights (no fuse - circuit breaker inside the headlight switch).
If none of them have power, then the break is in the circuitry before where they all join. Right?
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