[Sherylchriss]

I have an 03 Dakota, the other night I tried to run a new cig. Outlet in the dash. Iused a wire that you just plug into a fuse. We had to leave before I could finish hooking it up. So I unplugged the wire from fuse box. Next morning I drove to the station. On the way back it stalled. Had to have a jump. I couldn't go any faster than 5 mph. Got a code p0700. Half way home it snapped out of it and ran fine. Later it wouldn't start. Got a new battery. But now while driving the voltage gage goes to nothing. Gage light comes on. Truck still running fine. If you shut it off and restart it the light gage goes out for a little while. Was thinking the voltage regulator but don't know how to test it. Any thoughts on this. Thanks

 

[Burned]

ECM takes care of the voltage regulation. Have you checked across the battery while the engine is running with a multimeter?

 

[Burned]

If you find the alternator is not charging the battery and it bench tests ok, then you may need to bypass the ECM for charging.
External Voltage Regulator