just replaced battery, why???

:
2003.5 Black Protege5
my battery finally died, refusing to start the car or keep a charge

i swapped it out and now although the car runs and starts fine the "check engine" and "battery" lights remain lit

is there something i need to reset?

thanks
 
might have to re-set the CEL... i think you can remove the (-) batt termnal and pump the break. But im not sure... im sure someone knows how to do it.
 
ok, cool, hoping it is something that simple. i need an oil change so i might just take it to the dealer and have them reset it

just wanna know what i'm in for so they dont try to overcharge me
 
Yeah, I wouldn't be surprised if your alternator is busted and that is why your battery died. Get a cheap volt-meter at radio shack and test to see whether the battery reads 13v or more when the car is on (usually 13.9-14.4 is typical).
 
metered it and it was steady at about 13.33 volts until the defroster kicked in then it dropped to about 12.5 and went back up to 13.33 so it seems the alternator is working:)

i called the local dealership and the guy had no clue. he said to drive it for a few days and maybe it will fix itself(hand)
 
The voltage will dip when you first turn accessories on, but it should bounce back to the idle voltage after a second or two.
 
clean your battery terminals, and make sure they're tightened.

Battery light usually means something is wrong with the charging system.

the check engine light shouldn't be related.
 
I've got a similar issue...

CEL has been on due to a bad MAF. Prior to knowing it was a bad MAF (actually broken), I tried to reset the ecu by disconnecting the battery. When I reconnected the battery and started the car, I now have a red battery light on. The owners manual says the battery is not charging. So after starting the car, I disconnected the negative battery terminal and the car continued to run. I was taught that if you do this and the car dies, the alternator is bad. If the car continues to run, the alternator is doing its job.

Any other idea's? It has been this way since Saturday and the car starts up just fine and none of the lights have started to dim. I have already cleaned the terminals thoroughly...
 
i have been driving the car since i posted this without a single issue. i am almost due for an oil change so i will just take it to mazda and have them check it at the same time
 
I've got a similar issue...

CEL has been on due to a bad MAF. Prior to knowing it was a bad MAF (actually broken), I tried to reset the ecu by disconnecting the battery. When I reconnected the battery and started the car, I now have a red battery light on. The owners manual says the battery is not charging. So after starting the car, I disconnected the negative battery terminal and the car continued to run. I was taught that if you do this and the car dies, the alternator is bad. If the car continues to run, the alternator is doing its job.

Any other idea's? It has been this way since Saturday and the car starts up just fine and none of the lights have started to dim. I have already cleaned the terminals thoroughly...

That is not 100% true but for the most part it is.
 
Woops, I meant to edit my post...

After finding out I had a bad MAF, I left it and the other sensor in the airbox un-plugged. I didn't realize that was when the battery light starting coming on.

Bought a used MAF from another M247 member, plugged it up and the other sensor in the air box and both the CEL and battery light went away...

I read in another post of someone having a battery light come on with that other sensor in the air-box unplugged. Odd, but seems to be true.
 
Woops, I meant to edit my post...

After finding out I had a bad MAF, I left it and the other sensor in the airbox un-plugged. I didn't realize that was when the battery light starting coming on.

Bought a used MAF from another M247 member, plugged it up and the other sensor in the air box and both the CEL and battery light went away...

I read in another post of someone having a battery light come on with that other sensor in the air-box unplugged. Odd, but seems to be true.

hmm, maybe i bumped the airbox while installing the battery, i will take a look later today
 
^ maybe...

Did you find out what your CEL was? The two might be related...

Vato-Zone or any other auto-parts place should be able to read the code for you.
 
cool deal

looked under the hood and it was unplugged so i plugged it in. the battery light went away instantly, but the engine light stayed on.

i drove around town, stopped and started a few times and the engine light eventually went off after the third or fourth start

thanks for the help:)
 
^ awesome!

If the CEL comes back, I would get someone to read the code. If you didn't have a CEL before you replaced the battery, I wouldn't worry about it...

Glad I could help!
 
So after starting the car, I disconnected the negative battery terminal and the car continued to run. I was taught that if you do this and the car dies, the alternator is bad. If the car continues to run, the alternator is doing its job.

DO NOT ever do this to test for a bad alternator. I'm guessing the guy who taught you this still thinks that you need to set ignition points and adjust the mixture screw on the carburetor to smooth out a lumpy idle. This test was used 30 years ago when the only electronic item in the car was the radio. If you try this now, there is a very good possibility that you could get a voltage spike that damages many expensive electronic components in your vehicle (since you have removed the item which grounds those voltage spikes, aka the battery). And you will quite likely ruin your alternator in the process, so you will not know if it was bad to begin with or if your removing the battery killed it.
 
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