On my 94 B4000 (specs in sig) the voltage guage reads normal while the engine is running. However, when I shut the engine off, the needle on the voltage guage slams over to the edge of the guage (0V side) and sticks there. When I restart the engine, the needle will not return to the normal position unless I tap on the guage fairly hard. Other than that, the guage seems to work fine. I'm not exactly sure how to trouble shoot something like that and am open to any suggestions.