I have an F250 w. the 7.3 diesel The voltage indicator light is always on and it appears that the alternator is not charging the system (it's a constant 12 volts).
Here's the recent sequence of events which I think precipitated the problem:
First, there was a major short in the system which burned the ground wire from the engine block to the body. It was subsequently rewired and appears to be like before. However I noticed that when I turn on my headlights certain instrument gages (temp, oil) jump up a tick. I then did a voltage check on the 12 volt supply to the voltage regulator. It read out 12 volts. Then I tested the same circuit using a 12 volt light and noticed that the bulb output was much dimmer than if it was connected directly to the 12 volt battery terminal.
I then experimented and connected that same terminal to the + post. I observed this very carefully and noticed a little smoke billowing from the circuitry. Right away I disconnected the lead. I subsequently checked the 12 volt supply line again and this time no power whatsoever. Also no blown fuses were visible. I have some spare voltage regulators so if I fried that one it's no big deal. But I'm wondering if on my model there's a circuit breaker or in-line fuse that blew. Also where does the voltage regulator power connect to the system? At the ignition switch? On the steering column harness? Would a wiring diagram help?