My fan is close to 40 amps and I use a #10 wire and the correct matching pins in a weatherpak connector. Absolutely no issues. I suspect that you either had a bad crimp or undersized wiring or pins.

67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......