I have a 03 Mustang V6, and just recently have been dealing with my gauges flickering rapidly and resetting with ticking sounds every time I drive. At times it would slow my car down a bit then continue with the normal speed. At first I thought it was the alternator messing up so I went and had it checked out and had to buy a new alternator, even so it still continued to have the same issues. Is there something else I could try to get rid of this issue? Here's a video to show what it look...

Gauges, Radio, and headlights flickering while driving