I did the Big 3 on my Ford Focus last week:

4gauge from the Alt to the Battery.
4 gauge from Battery to Body.
4 gauge from Engine to Body.

Now I start my car and the Volts are stupid high.

Volt meter reads 15.1

Amp reads 15.1

Car runs great But now im worried about cooking the Alt.

Any advice.

When i crack the System the Volts go up a bit more.