Two winters ago, at the beginning of winter, My DCTD began to show intermittent signs of charging system failure. Voltage was at battery level and after a bit the GEN light would come on. Switching the key off and on took care of this. After only a few times, the problem seemed to go away. From the way it happened, I was pretty sure it was probably a voltage regulation problem.

Additionally, one thing I learned about my DCTD that winter is that it is a "sled". It's so big and heavy that, even with 4WD, it doesn't like to stop on snow and ice with summer tires on it.

At the beginning of last winter the charging system failed completely. Feeling a bit disenchanted with the truck, I decided that I would not spend $700 to $800 to buy a set of studded tires for it and would not expend the effort to diagnose and fix the charging problem at that time. Being as I'm a "shade tree mechanic", I figured spring would be soon enough. So, I parked it for the winter in disgust.

After deciding that it would be cheaper to take it in to be diagnosed rather than buying all the tools and equipment to do the diagnosis myself, I finally took it in.

I was absolutely amazed. The alternator had died. Per the mechanic, the intermittent failure of the alternator as temps cool down is not all that uncommon. I had convinced myself that it was probably the computer that needed to be replaced. I had never seen an alt/gen fail like that before. You learn something new every day.

FF

 

If you do a search, Haulin' posted a proceedure of how to put a new voltage regulator on in place of the computer. He also said how to tell if it is the alternator or not. Turns out to be "fairly" easy too. At least you got your truck going again.
Tom