I am having trouble with the volt meter in my 83 H/O. It don't seem to be registering correctly. I have had the alternator checked and it is good but when the car is running at any rpm the voltmeter doesn't seem to want to register at the most around 10 or 11 volts. I checked the input prongs that hook into the gauge in the back and it shows hot on one but not on the other. Is this the way it should be. I was thinking that voltage would come from one post thru the gauge and back out the other post. Hopefully someone can help me with this.

 

Not sure about your car, but most voltmeters have a + wire and the other is just a ground. Have you tested volts at the Battery? What volts do you show on the hot side?