I would charge and check the batteries and check the alternator. Your battery light didn't light in the dash? Does it come on at key on with all of the other lights?

 

Alternator highly suspect with those symptoms - dash light or not. Dash lights can burn out.

 

I am not trying to talk down to anyone reading this, but here is a simple way to check alternator operation.
The batteries will need to be charged enough to be able to start the engine.

Get a voltmeter and check the battery voltage, note the reading, a digital meter is preferred but not necessary. Start the truck and wait for about a minute or two, enough time for the glow plug relay to timeout. Take a reading. If the reading with it running is higher than the reading while not running then the alternator is charging. If it's lower then the alternator is your problem. Check wiring, if fine, replace the alternator.

 

Took too long to type! Tugly and axmrdr beat me to it.

Definitely have both batteries and your alternator tested.

I'm not saying this is your issue but it sounds like your alternator is bad and not charging the batteries. The batteries have been running everything and have finally lost enough potential to run the truck and it finally shut down.

Again, I'm not saying this is your problem but it sure reads like that. Colorado350 and Walleye Hunter have good recommendations to get you going down the right road. If you have a multimeter you can check a few voltages to give you an idea of what might be going on. Your batteries should be around 12VDC. You want to lift one of the cables off the terminal so you get a true reading on the battery otherwise you will be getting a balanced reading between the two. Even in you do get 12VDC (ish) it does not give any indication on cell health. You will have to get it load tested at a local auto parts store for that (they do that for free). I had a couple of Optimas that were reading around 12VDC but would not start the truck. Had them tested and 1 battery had 5 dead cells and the other one had all 6 of them dead.

Once you get the truck started take a reading of the alternator output. You can take this across the alternator or battery terminals (recommend the driver's side since that's closest to the alternator). You should be reading around 14VDC (definitely over 13VDC). This will indicate if your alternator/voltage regulator are working correctly.

Again these are basic tests you can do at home to see what might be the issue or what you want tested. For confirmation I recommend having your suspect component(s) tested by a reputable shop/store before you start throwing money at it.

Just my .02

I had an issue similar except my battery light came on. Took a reading and I was at 10VDC with the engine running. I had no choice (and I definitely don't recommend it) but was able to commute to work for 3 days (60 miles round trip) while waiting for replacements. I minimized all loads (A/C, radio, lights) during that time. By the 3rd day I could tell that the batteries were getting tired.

 

 

Where are you taking your voltage readings from? Battery 1 and 2? Both should be in sync while key off and with engine running.

A bad ground or any positive lead will spill the voltage as described. Trace the leads from your batteries to block and clean all thoroughly. Pull your starter positives (batteries disconnected) and clean clean clean. Check the top of alt and make sure the connections are true.

A test from your pos alt post to ground will give you a true reading if indeed you have output.

Bad ground, poor connections are my go to if the alt does test good.

Keep in mind the 2 min delay!!!

Denny

 

I'm suspecting bad connection(s), make sure that your connections are clean, check your battery voltage from the posts themselves and see what you get while running, it should be 13V +