Electrical problem

Welcome to 2CarPros.

That is a concern. On this vehicle, the voltage regulator isn't a separate component. On the diesel, it is part of the engine control module (ECM). Now for the worse news. The ECM isn't serviceable. When the electronic voltage regulator (EVR) fails, the ECM needs replaced.

I attached a picture of the ECM location. It is number 16 in the pic.

If you decide to replace the ECM, they are no longer pre-programmed from Chrysler. It will require a specific type of scan tool to program it for your vehicle.

Let me know if you have other questions.

Take care,
Joe

Hi Joe. I suspect you're overlooking something. I can't get into AllData to look at the wiring diagram, but the clue is two different voltage readings on two different batteries. Unless there's something I'm not aware of, those two batteries should be connected in parallel and should always read the same voltage. Could here be a bad connection on one of the battery cables, or something in between them? That might take one battery out of the circuit where system voltage is sensed, making the voltage regulator see the 12 volts, and raise charging voltage higher and higher in an attempt to get that up, and the result is the 18 volts in the rest of the system.