I have a Focus that drives great for about 30-45 minutes then dies. All the lights in car start flashing. The car will turn over but won’t start. The lights flash for approximately 15 min and stop. But car still won’t start just turns over. You can let it sit overnight and it will fire up and the cycle will start over. Please help.

 

It looks like there is a problem with your alternator, or just the voltage regulator. But on yours the voltage regulator is internal and not replaceable itself. Before buying a new alternator do some testing, and check the wiring as well. As far as testing, get voltmeter check battery voltage at rest, and in the morning try to start it up and continue to monitor the voltage, do you get at least 13V something?