> The batteries have a good charge though, could a low voltage on the alternator cause this?
What is the voltage across the + and - terminals of the battery before you turn the ignition on?
It is easy to determine if the alternator is your problem. When the engine is running it should be applying a charging voltage to the batteries. 1) check the battery voltage before turning stuff on. 2) start the engine. 3) a high idle is good, now check the voltage across the battery terminals again. It should rise from about 12.6v before you start the engine, to 13+ volts after. If the voltage doesn't rise that far after a few minutes then you need to figger out what is not working.
What is the voltage across the + and - terminals of the battery before you turn the ignition on?
It is easy to determine if the alternator is your problem. When the engine is running it should be applying a charging voltage to the batteries. 1) check the battery voltage before turning stuff on. 2) start the engine. 3) a high idle is good, now check the voltage across the battery terminals again. It should rise from about 12.6v before you start the engine, to 13+ volts after. If the voltage doesn't rise that far after a few minutes then you need to figger out what is not working.