I was always told one way to check if you had a bad battery vs. a bad alternator was to start the vehicle and disconnect the battery. If the car continued to run then it was most likely a bad battery, if the car stalled out, then it was the alternator.
Tested this with my car (with power windows, locks, electric fuel pump etc.) a few months ago, and the car continued to run with the battery totally disconnected.
I had the same problem a few months ago (though wasn't hauling anything). Get it checked out sooner rather than later.
It was my alternator. Came on while I was driving, battery gauge was low, but was in a situation where I couldn't do anything about it at the time. Next time I started the truck it was gone. However, it reappeared within 15-20 minutes.
The next day it again started with no light, but came on sooner than it had before. I stopped by an auto parts store, guy who helped me said there was some corrosion on the battery and it might be that but otherwise he suspected alternator. Cleaned up the battery but that didn't seem to make a difference. The next day truck wouldn't start while leaving the lab I worked in late at night...got a jump, drove for *maybe* 2 minutes before I lost power to everything...no lights, no power steering, truck kept acting like it was going to stall out. Went to my closest friends house for the night (needing one more jump after sitting at a stop light) and managed to limp it to the mechanic in the morning. Would have been wayyyy less of a hassle if I had taken it in earlier!
We have owned several 2000 dodge diesels. DH is mechanically savvy avd says it was probably the alternator if the truck restarted. He says if the gauge stays low (at 8) the truck could stop while you are driving it.
He says some diesels are more sensitive to electricity and so some will run fine with poorly charged batteries than others. Of course you need a good alternator if you have junk batteries. (I think I explained that right).
Battery issues would have caused your truck to start hard/turn over slowly.
How is it today? DH says driving thru a lot of snow can cause the belt to slip and be funky for a while. He says it's really three options... Battery, alternator, Belt
THINE own post. Heh heh. THY post, as in THY post is wrong. THINE own post becase THY before a consonant, THINE before a vowel. Or before nothing. It is THINE. As in it is MINE. You wouldn't say It is my.
Today we might say "MY own post" but in the old days it would have been "MINE own post" and "MY post." Comes from the french penchant for not having two vowel sounds together.
Just sayin'. Mine own opinion.
Trainer's website - photos of my horse Airborne under About and Francesca Edwards also in media page 1