Battery Light and Brake Light Flickering Intermittently

[SomeOldDude]

Folks,

I've got a 96 Maxima with almost 90K miles on it. It's in great shape, by
and large, but I've had a little problem lately I can't figure out.

Occasionally, particularly at lower speeds (in slow traffic, f'rinstance, or
at speeds under 35 MPH), the battery light AND the brake light will flicker
on, fade in & out, and eventually flicker off (generally as speed
increases). Putting the car in neutral at a light and slowly increasing the
RPM doesn't seem to have any effect.

I've already checked the stuff that was easy to check, i.e., visual
inspection of the battery connections (looked good... and the battery is
only about a year old) and visual inspection of the belts (looked okay to
me, too, but couldn't get my hand down in there to check the tension).
Can't really check the alternator/regulator situation out myself.

I guess the big conundrum here is why the battery and brake light would both
come on at the same time. If it was one or the other, it would make more
sense, and I'd have an idea where to look, but this confuses me. And
they're definitely in sync: they flicker on at the same time, flicker off at
the same time, and fade in and out simultaneously. I'm beginning to think
it's a warning light conspiracy.

Any ideas?

Thanks,
Keith

[David Efflandt]

Post by SomeOldDude
Folks,
I've got a 96 Maxima with almost 90K miles on it. It's in great shape, by
and large, but I've had a little problem lately I can't figure out.
Occasionally, particularly at lower speeds (in slow traffic, f'rinstance, or
at speeds under 35 MPH), the battery light AND the brake light will flicker
on, fade in & out, and eventually flicker off (generally as speed
increases). Putting the car in neutral at a light and slowly increasing the
RPM doesn't seem to have any effect.
I've already checked the stuff that was easy to check, i.e., visual
inspection of the battery connections (looked good... and the battery is
only about a year old) and visual inspection of the belts (looked okay to
me, too, but couldn't get my hand down in there to check the tension).
Can't really check the alternator/regulator situation out myself.

It sounds suspiciously like a charging problem, but it could be just a bad
connection somewhere. Check voltage at the battery and somewhere in the
car when that happens (like lighter socket). Not sure exactly what
it should be, but I would guess that somewhere around 13.5 volts would be
normal, below 12.5 would be low (12 or below very bad).

I have never had charging problems with my 95 (purchased May 94), but I
just purchased my second replacement battery this summer. First battery
lasted 5.5 yrs, 2nd maybe 3.5 yrs (credit towards replacement).

[Richard Tomkins]

I had exactly the same problem. I let it be and after a month or so, it went
away. It was exactly the same with my VW Scirroco. The brushes in the
alternator were not making good contact all the time. After they wore down
some, everything was fine.

Check the charge voltage though just to be sure, should be 14VDC or slightly
above.


http://uuhome.de/william.darden/carfaq5.htm


rtt

[Nick]

When both the battery and the brake light flicker, it is the alternator
over/under charging. When was the last time you changed your belts? They may
be slipping causing the alternator to undercharge. It could also just be a
bum alternator. Have it checked out and replace it if its gone south. If you
ignore the problem, you'll probably be reducing the life of your battery or
at worst, toasting a few electronics if its an overcharge situation.

Nick

Post by SomeOldDude
Folks,
I've got a 96 Maxima with almost 90K miles on it. It's in great shape, by
and large, but I've had a little problem lately I can't figure out.
Occasionally, particularly at lower speeds (in slow traffic, f'rinstance, or
at speeds under 35 MPH), the battery light AND the brake light will flicker
on, fade in & out, and eventually flicker off (generally as speed
increases). Putting the car in neutral at a light and slowly increasing the
RPM doesn't seem to have any effect.

<snip>

Post by SomeOldDude
Any ideas?
Thanks,
Keith

[Stovebolt]

SomeOldDude; I just joined the group and I don't have a solution for your problem.....BUT...I have EXACTLY the same problem with my 94 Maxima. If you have found a solution by now I would sure appreciate you telling me what it is. I don't know if you noticed but when it's dark and while the brake/battery lights are on the headlights go dimmer than normall. I'm afraid to drive it until I fix it.

[Nick]

When the battery + brake light's flicker, that is a bad alternator.

Nick

Post by Stovebolt
SomeOldDude; I just joined the group and I don't have a solution for your

problem.....BUT...I have EXACTLY the same problem with my 94 Maxima. If you
have found a solution by now I would sure appreciate you telling me what it
is. I don't know if you noticed but when it's dark and while the
brake/battery lights are on the headlights go dimmer than normall. I'm
afraid to drive it until I fix it.

[Jim H]

I agree, ALT probably bad, battery weak. New ALT, new battery, good to
go............

Post by Stovebolt
SomeOldDude; I just joined the group and I don't have a solution for your

problem.....BUT...I have EXACTLY the same problem with my 94 Maxima. If you
have found a solution by now I would sure appreciate you telling me what it
is. I don't know if you noticed but when it's dark and while the
brake/battery lights are on the headlights go dimmer than normall. I'm
afraid to drive it until I fix it.