Amp to volt gauge replacement
The old thread posted above is the only go to I know about. I was happy with mine, left the original needle on the voltmeter. Some guys superglued the old ammeter needle onto the new voltmeter to better match it. I used the face of my ammeter, and there is a pot adjustment in there, so you can set 14V right at the ammeter center scale. This of course causes the meter to run "centered" just like the ammeter with the battery charged and normalized and running