95 K2500 intrument cluster question

My volt guage on my 1995 K2500 always reads around 9-12 volts with lights on or off and the battery doesn't run down. The other guages seem to work fine. Has anyone had this problem? Can I take my cluster out of my 96 and put it in there to see if that guage does the same thing? Or will it mess something up?

I had a 97 Silverado with a 350 and the voltmeter always read around 12-13, when in fact they should all read around 14-14.5. The gauge was spot on as confirmed by my multimeter. The truck ran fine (electrically speaking) although it did have other problems that were unrelated.