Sorry if this is a repost, but I just didn't know how to search for this.

My car (04 MT) seems to have a "weak" battery - when I flash my brights, or when I'm slowing down and braking heavily, or turning into a parking spot, the electrical in the car will shut off for a second and restart when the load has gone away -- the dash will go dark for about a half second, then you see "Mazda RX-8" on the radio, the ABS and other lights temporarily on the dash.

About a year ago I had this checked out and the shop said the battery was holding an extremely low charge, and that I just needed to replace it. Well, I did, and it was fine for about six months - now the new battery is doing the same thing.

What is weird about this is that it is always fine after a second I can turn on my brights and most likely it will do this, but then come on and be fine. And the other weird thing is it has NEVER had a problem starting right up, even in extremely low temperatures or other conditions where I would think a battery might show problems.

Has anyone else experienced something like this or have any idea what I can have the shop look at? The only electrical mod I have is the fog light rewire, but it's rewired to the parking lights, so unless my wiring has gone bad and is shorting out, it shouldn't be a problem. I also have an amp (300W) but this was happening before I added it.

 

Any ideas out there? No one has experienced anything similar?

 

could be a bad alternator

 

Check the connections on your battery. Make sure the contacts aren't dirty and that the connections are firm.

If that's ok, I'm thinking you could have a short or an issue with the alternator.

 

i'm going to say alternator. cuz once the car is going it should be running on the alternator. not the battery

a weak alternator would also explain the low charge on the battery

 

^..........yep!
Wonder if he's got a meter?
If not, go to an Autozone or simliar, they might check it for free.........my Autozone does.

What's your location Nick? Should add it as it really comes in quite useful.

 

I think people keep forgetting that a battery is still being used while the car is running.
It regulates the voltage supplied by the alternator to keep it close to 12V.
You don't want 14V plus load changes as RPMs increase surging through your electrical equipment.

 

Thanks for the answers, I will head to Autozone and see what they can check out. Unfortunately I left my dome light on over the weekend and now the battery is really dead.

I'm in Utah, I added it to my profile.