318 ammeter erratic?
My buddy had the same issue and we swapped out the ballast resistor and it fixed his issue as well. I don't think that its a coincidence
Let me explain something. Just because you, or your buddy, or your cousin's uncle's daughter's brother in law did "something" and it cured "something"....................
that does not mean that "something" was the cause.
You are "up there" at the firewall. There is a LOT of harnessnessly "goin on." You have connections, you have the bulkhead connector. ALL these OLD connections on these old girls are suspect nowadays. Hell, they were suspect when these cars were 5 years old, and in some parts of the country (rust belt) they were an issue when TWO years old.
So you get in there.
You wiggle stuff around. You replace the ballast and "it works." Hell it's happened to ME. And I think HEY!!! FIXED!!! Until a week, or two, or three later.........and the problem ....is... ....back
IF this "fixed" the problem it's because you have A SECOND PROBLEM. You have VOLTAGE DROP caused from BAD CONNECTIONS in the circuit path FROM THE BATTERY............THROUGH ALL THE CONNECTIONS...........SUPPLYING...........THE IGNITION.........AND THE.........REGULATOR............terminal
The simple fact is the "several amps" that the coil and ECU draws is NOT enough to adversely affect the charging system unless there is a separate problem.