battery light

[bbc20000]

I have 2004 Mazda 3. Red battery light stays on when I start engine but it then goes away after 20 - 25 minutes driving and it does not come back until I leave the car off for a long while. i do not have problems starting engine.
what might cause this problem

[McGuyver_3]

have your battery checked out may be possible that your battery is dropping below a certain level the car picks it up and sets off a light and once the battery is charged up the light distinguishes. Do you drive your car alot? Do you do more short trips or consistant long trips? If your battery light would stay on consistantly i would blame the alternator but deffinatly have the battery checked

[kramr]

I would have an AVR test done on the alernator. Could a weak alternator, brushes sticking and/or glazed and/or worn enough to cause a poor charge after it starts and loosening up when running for a bit no to mention the heat may help it a bit. Could be a combo of both battery/alternator. Usually when the battery light is on, it is the alternator that is screwed up. I have seen time and time again a car come in with a battery light on and a brand new battery under the hood because the customer thought that since the battery light is on it must be the battery. Indirectly yes it is, it is not getting the proper charge in a lot of cases.!
:blah

[froggy]

do you have any aftermarket electronic gizmo's that might be drawing juice while the car is off? if it's not the alternator or the battery it could be the leads coming to and from each, damaged wire, loose/corroded terminal.

[bbc20000]

do you have any aftermarket electronic gizmo's that might be drawing juice while the car is off? if it's not the alternator or the battery it could be the leads coming to and from each, damaged wire, loose/corroded terminal.

no i do not have after market parts. is alternator replacement expensive for mazda 3 ?

[froggy]

no i do not have after market parts. is alternator replacement expensive for mazda 3 ?

I wouldn't know as I'm still new to the mazda myself, but by judging from it's location on the engine I'd say no, at least from the installation side of it. How much an actuall new alternator or rebuild or aftermarket alternator will cost I have no idea.

[MRT_MS3]

no i do not have after market parts. is alternator replacement expensive for mazda 3 ?

OEM alternator will be around 300-400$, rebuilt alternator from 100-120$ and
labour around 90-130$.

[SKYMP3]

Isnt this belong to the sub section about Problem with a Mazda 3? instead of posting here in the mazdaspeed3 forum.

[S.F.W.]

thread moved.