Previous owner went through 3 alternators before I got it. When I got the car, it was very unhappy about heat and would drop to 12.2 volts.

I made this using an an old cookie sheet just for testing. It bolts up to power steering pump bolt. I have never seen my alternator drop below 13.2 since

The cookie sheet is starting to crack in the corners. It was pretty flimsy. My next iteration of it I will use thicker sheet metal and wrap it in fiberglass wrap.

Also add some new grounds. Especially to alternator if you can. Also check for shorts in wiring.