Headlights "Blink" with Brake light

I have 2000 PA with 74K miles. I have an unusual problem, I have never encountered before. When I step on my brakes my headlights will blink for an instant. It's barley noticeable, but it bothers me and I wonder if it is a tell for something worse to go wrong. Also, my voltage will quickly travel from 12.4 to 13.7 volts while driving, for no apparent reason approx 2 times per minute. Any help will be greatly appreciated.


Thanks

sounds like an alternator or battery about to retire.

I have 2000 PA with 74K miles. I have an unusual problem, I have never encountered before. When I step on my brakes my headlights will blink for an instant. It's barley noticeable, but it bothers me and I wonder if it is a tell for something worse to go wrong. Also, my voltage will quickly travel from 12.4 to 13.7 volts while driving, for no apparent reason approx 2 times per minute. Any help will be greatly appreciated.


Thanks

Mine did this too. Tighten the batter connections....the ones on the side of the battery. I read a post here a few weeks ago and it cleared up a lot of problems.

I lived with it for awhile...but it got to the point of losing the memory settings. I'd start the car and it would say unknown driver.

Anyways, tightening the connections took care of this and keeps the voltage nice and constant.

You might remove, clean, and reattach those connections. Check them all.

Thanks for the help, turns out the positive battery cable was loose.