I have a 06 2500 5.9 and the batteries keep over charging I can't seem to keep both batteries good longer than 6 months. I have opened the hood to the battery cap completely off and battery juice all over the engine and hood. My question is what to do to fix it?

 

Why is it over charging? Bad PCM? Any CEL codes?

 

how much voltage?

could be bad alternator or bad pcm...definitely don't ignore the issue as it can result in a dead ECM and fried electronics all over.

 

Here is how you test your alternator on the vehicle, over charging is sometimes by a loss of ground between the alternator and battery.


How to test your alternator on the vehicle:

To check to see if your alternator is working, unplug or remove the two field wires from the back of the alternator. Then ground one of the field terminals on the alternator and jumper the other field terminal to the positive battery post on the back of the alternator. It does not matter which terminal is grounded and which one get positive power. When you connect the ground and positive wires to the field terminals you will get a small spark, this is normal. This is by-passing the voltage control and will cause your alternator to run full blast, if it is working. Put a multi-meter on your battery and run your engine on high idle, do not allow your alternator to charge the battery much over 16 volts. If you find that your alternator is charging when you do this procedure, but does not charge when you connect it back to the computer, this kit will get your alternator working and charging at the proper voltage. The voltage regulator in the ERCKFRM kit is preset at 14.5 volts. If you want to adjust the voltage regulator you use the screw on the back, but be sure the metal case of the voltage regulator is grounded while you adjust it.

Ref: QSERCK , ERCK, FRM, ERCK-FRM