After Market Ammeter?

As I have the car's instrument panel out, the wiring diagram shows a 12 gauge red with tracer going to an accessory circuit breaker. This wire was not on the ammeter. Anyone know what the deal is on this??? Thanks

You MAY have what is known as factory? dealer? "police / fleet / taxi" wiring. This is documented in some of the service manuals. Look for big black and red wires going through the firewall in separate grommets, that is separate from the bulkhead connector.

Otherwise, someone has "beat you" to a bypass project