May I add that I simply am not comfortable with voltage levels exceeding 14.7. Blizzard weather helps to cool components but even down here I see 14.4 - 14.6 @ 75F ambient. And I am switching to a group 29 AGM. When travel in excruciatingly hot weather I am going to dial battery voltage back to 12.85. The battery will be under-hood. Short runs around the village - 14.5 volts.
A 100-watt resistor is going to run less hot than a 50 watt. These alternators have a 3.0 ohm rotor coil. At 14.5 volts = 4.83 amperes or 70 watts. You can come to your own conclusion about component life-span.
It's about time I email Marles, and request the Megawatt .002 cent pot get replaced with a vertical multi-turn pot. They do make 3-turn 500 ohm pots and they would be cost effective.
