Around 1000 rpm, my headlights (most noticeable)
dash lights and interior lights dim. Always when
braking or decelerating. And only for maybe a
second or two but it gets very dim. Sometimes the
radio pops out for a split second as well but goes
back to normal. I just had a new alternator put in
and have driven on it quite a bit to try to get it
“broken in” per say. But nothing has worked. The
tests on the old alternator came back bad so that’s
why I got a new one. This still happens on the
replacement. I’m not super knowledgeable on cars
but would love to know what’s going on. Thanks!
Check the output voltage of the alternator. The battery may be weak so have it tested.