With lights on, a/c on , foot on the brake, and turn signal on my volt gage swings at least a volt with the turn signals. I have an after market gage in the pod so I am not relying on the factory gage. I also backed it up with my volt meter on the batteries and have replaced the alt. twice but still have this issue. Thanks for your help

 

Had the same issue was the alt lucky it was under wty replaced it now 14.5 all the time was at 10.5 and 12 good think I was having issues with the remote starter who I would have ruined my brand new red top optima batteries. Have it tested again by autozone or someplace and you could just have another bad voltage regulator.