My 1680 would run for about 2 hours until the reel control and feederhouse would start to lose power. Mechanic ran a new ground wire and problem was solved.
I have a 1640 that does the same thing with the lights. I believe the breaker-solienod is too small. I unplugged some of the work lights that are not needed. That solved the problem.
Our 2388 did the same thing until we replaced the headlight circuit-breakers (that are located in behind the sun-visor) with fuses 5 amps above what the breakers were rated at. This fixed the problem for good. Cheers Henry