I noticed this more at nite when I have the headlights on, but I'm sure it does it in the daylight time too. But if I'm cruising and then apply the brakes to slow down, I noticed the headlights flicker a bit for a split second. All the electronics flicker a bit too. The other nite, my wife had the passenger visor mirror and light on. And I noticed the mirror light flickered too.

Any ideas whats causing this? Would a grounding kit help? Its kind of annoying.

 

I have this same problem and I have a grounding kit. Didn't really help. I also replaced my battery. Voltage regulator?

 

old alternator.

 

I agree too. If you have over 100K miles on an original alternator, change the brushes. Hand turn the shaft to make sure the bearings are ok.

 

When you use grounding kit, make sure you clean ALL grounding locations. Can't put new wires on dirty spots and expect better current flow.