[RICK LAKE]

GUYS Here's the problem with a curcuit breaker, It protects the wiring curcuit from over load. Downside. IF you have a wiring problem like the amp gauge problem here and the power wire shorts to ground, it will blow and open the curcuit. HERE'S the problem the curcuit breaker cools off and resets. These thing will reset from 10 - 50 times. Each time the problem is grounded and burns the wire coating. Over time you get a melted wiring harness.
Slow blow glass fuses worked for alot of years in a car or truck. They are now plastic and cheaper to make but still do the same thing. If you want to save your wiring harness from burning up, install a maxi fuse and holder. It's not orginial but will protect the wiring harness of the car. You have them on most new cars and truck. They range from 80 amps to 250 amps. It only blows once. Have to find the problem but alot less damage to wiring harness. I have a 100amp for my wiring system and a fusible link of 125 amps on my ALT.
Side note all fuses are measured for ampage ratings of constant load. The problem is when a curcuit is turned on, like lights the amp spike instead of 10-15 amps is 30-40 amps for a split second. This is the reason for slow blow fuses.
Late note IMO wouldn't recommend running parallel curcuits. If you run 2 wires to and from the same terminals and one shorts out. Unless you cut it out of the curcuit it's only going to burn up the other curcuit too. ERA wiring harness is just fine. Issue again is the insolators of the amp gauge from SW or Smith. Theses gauage where not designed to handle 60 amps constant and spikes of over 100 amps on startup if your system is wired that way.
If you want to run the oem look of an amp gauge, leave it unhooked and run a voltage either under the hood or in the glove box to keep a check on the battery and charging system Rick L.