I did the upgrade as MAD recommends. I also installed relays for my headlamps and for my dual electric fans. BTW, having a parallel feed through the bulkhead halves the current through the small bulkhead connectors which is the weak point.
If I remember correctly, the madd electrical bypass shows doing away with the bulkhead connectors for the two wires we’re talking about. And drilling out the plastic and running continues wire through and back out, thus eliminating the connectors altogether. At least that’s how I did mine
