05 Cummins 600 charge problem

2005 3500 cummins 600, auto. On startup, hot or cold, volt meter shows battery voltage (no charge). I have to get out on the road before it swings over to the charging side. Also instrument cluster lights cycle bright & dim with corresponding relay clicking from right kick panel. I've tried 1500 rpm in the driveway for 30 seconds and no help. Going to the dealer next week. Any body seen this before?

yes, don't worry about it. What is happening, is until a certain level of intake air temp is reached, the intake heater grid continues to cycle on and off. that unit draws approx 300 amps at full power, so it draws the alternator and lights and so on down with it.

I had the same issue when I bought my 01. did some reading, that put my mind at ease.

Happy motoring, and remember, " If it ain't CUMMINS, it's just breathin hard"