I will start out with a little history of the situation. A little over three months ago my original altenator died with over 200,000 miles on it. I took it in and had it replaced (they used a refurbished altenator) and about a 1-1/2 months later is when the issue started. The headlights and dash lights will flicker and whenever they dim, the volt guage will go down. When the lights come back to normal brightness the volt guage will also go back to normal. All this will go on for random lengths of time as I am driving. I took the vehicle back to where I had the altenator replaced and they replaced it again under warranty. About another 1-1/2 months went by and the same thing started happening. I took it back to the same garage and this time they put in a brand new altenator. Finally about a week after this last visit to the garage the symptoms came back. Does anyone have any idea of what could be causing this? Thanks ahead of time for the help.