Ammeter stops reading

[mopardug]

Hi Sportsfans, I had a problem coming back from Paducah yesterday.
'04.5 Cummins Crew Cab dually 325 HP, 2WD, six speed. 253K on the clock.
I shut her off while I fueled up. When I started her back up, the 'check gauges' light was on, and the Ammeter needle wasn't reading at all.
The gauge started reading for about a minute, once on the way back.
The ignition switch seems to have a little movement. A couple of times I'd turn it on & off while driving, and the gauge would momentarily read, and then drop all of the way down.
After we got home, about three hours later, I shut her off, and started her back up. The gauge started reading normal.
We had to leave so I couldn't look at her any longer. When we got back for the night, the batteries didn't seem to be low.
Could I have a bad ignition switch?
If this is the wrong forum, please feel free to move it.
Thanks for looking.

 

[67Dart273]

I'm pretty sure you have a voltmeter an not an ammeter? But regardless, I'd have to take a look at the electrical layout in one of these. It might be the voltmeter is powered directly by the key but it might not be. In other words "through a relay."

Did anything else seem to be dead? That would be a big clue. I doubt the meter is powered by a complete dedicated circuit, it likely is tied to other components. If the owners manual has a list of fuses and what they serve that might give you some direction

If it simply quit charging, the meter should read low, not zero

 

[mopardug]

That's what I thought, that it would read low. But it doesn't move up at all. Everything else seems ok