2002 Dodge Ram 1500, 4.7L Engine
Voltage gauge went all the way to "H". Disconnected battery and had it charged. Battery is still holding the charge. Reconnected battery, but have no power....just a steady red light on the instrument panel. Red light seems to be a security device (immobilizer). How do I resolve this issue without having to take into a dealership?

 

Depending on how old the battery is, it may need replaced.

 

Battery is about 2.5-3 years old.

 

Try a different battery... if your voltage gauge went that high you might have fried some fuses, so check all of them as well.

If the voltage spikes again then you might need a new voltage regulator....