Alternator gauge question

The MAD approach should fix most of the problems, but a simpler approach would probably get you there. Run an 8 awg wire directly from ALT big stud to BATT+. Run it across your timing cover and put it in sheath (split loom or smooth PVC). You can leave your ammeter connected, but it won't read much since now bypassed (unless you follow my post w/ the bypass diodes).

Remove the 2 bulkhead connectors for lights and engine (can leave the wiper plug as is) and remove each male terminal (squeeze long way w/ needle-nose & wiggle) and clean each w/ sandpaper (one at a time, don't mix them up). Clean the female terminals (cabin side) as best you can with a small file, then spray with contact cleaner (hardware store). Squeeze silicone dielectric grease in the female terminals and reconnect. For anything that is still erratic, remove the connectors in the engine and/or cabin and do the same.

For broken (or almost broke) wires, solder and cover w/ heat shrink. Do the same for any wires you find with the clunky butt crimp "repairs" that every clueless mechanic uses.