Dead battery

What Condo said. Most vehicles can put out max amperage just off idle, say 1000 or 1200 rpm. Anything higher is just noise and wasted fuel.

 

You ought to be careful .
It may be a 24 volt starting system. It can get complicated .

 

It won't hurt to boost it off your car. Just give it a good 15 minutes to build your dead batteries up a little. Use proper jumping techniques. Go from your car battery hot/negative to the hot post on the firewall of the truck in front of the driver. It should have a red cap on it. The negative hook to something metal under the hood like a frame bolt (chassis ground).

If it's cold up there it would help to plug the block heater up for an hour or two. Though not the best for a diesel, if you are still having a hard time, as a last resort pull the air filter out and give it one 2-3 second shot of starting fluid if you have some. It'll start then with minimal cranking.

Your truck should have 3-4 batteries. You probably have a weak one in the mix. I would get them checked out later on. Also if you park near a power outlet Walmart carries a great battery maintainer for $20 (schumaker). That might save you next home time. It'll keep the batteries fully charged and turn off and on as needed.

Invest in a good set of 4 gauge 16-20 foot jumper cables and keep them on the truck.

 

Must be I used the odd car lol, cause when I jumped my truck the other day it pushed more volts the RPMS in the car.

 

Alternator may be going bad

 

I doubt it, with just the cables hooked up and the car idling the truck was reading just over 10 volts, when the engine on the car was idled higher it would go to 12.

 

Actually the its max voltage is probably well above idling speed.

 

http://www.qualitypowerauto.com/pages/AlternatorFAQ.php

 

Put a DVOM on yours and watch how it performs at idle vs higher rpm's.

It should read in the 14.0V range with the cables hooked up unless you do have a bad battery loading it down. Definitely check your batteries after you get them charged back up again. Remove the battery cables isolating the batteries and check the battery voltage again. I bet three read 12V and one will still read 10V because it has a dead cell which is why your batteries are dead in the first place. The truck has a low voltage shutdown but it is after the batteries. Cold weather will slowly drain good batteries but not in a week. Cold will get a weak system quick.

Also check the voltage on your car. Running it should be 14-14.5V. 13.5V the alternator is worn, 13V head to a parts store because it won't be long. You shouldn't have to raise the idle on today's vehicles to to get 14V. Back in the 70's you might or older hotrods. That website even shows an old wiring diagram. He must be an old fart. A lot has to do with the load put on it too if you have a dead short.