Truck wont start

That sounds kinda like the alternator i suggest changing that

I realize you may have checked some of these might be causes, but I'll ask anyway.

- Is there battery power to the headlights. If not Check battery connections for breaks and corrosion. Corrosion is enough to not let power flow. Make sure battery terminals are clean. Use baking soda and water solution to clean the greenish white stuff off. Keep in mind Sulphric Acid is bad for skin... Use wire brush.

- If you have a voltmeter/Battery tester check voltage at battery. should be at 12. 0 to 12.6 volts. This means battery is fully charged. If not boost battery. Then try starting vehicle if you hear the engine trying to crank over. You know your starter motor is working. If you hear just a clicking noise, but all your dash panel lights work and warning symbol come on. I now suggest that you take a hammer and hit the starter motor, not hard enough to damage it, but hard enough to help move the internal brushes around. If your truck now starts, Starter motor needs to be replaced.

I'm not saying that it isn't your alternator either, but I have a hard time just saying Alternator because you were moving down a highway, I'm assuming at 60 km an hour or more. This should not have let your vehicle stall out as a result of Alternator lack of charge. Have you ever sat in your truck at night with engine at idle and when you touch your gas pedal, your lights get slightly brighter, thats because you've moved the speed of the alternator up, producing more power. So as said before check battery voltage, if at 12.0 12.6 Check connections. If not boost batteries, if still doesn't start, but you have power to your headlights, next tap that starter motor. May be hard to get to, but try. Should your vehicle start after boosting, keep an eye on your dash. If your battery light comes on, this is a good indication that your Alternator is the cause. Hope I've given you something to go by.