Hey guys, new here, from Guelph, Ontario, Canada.

Just recently bought a 30th anniversary 2003 Honda Civic LX 4 dr.
Its got 234,000 km on it.

I've got a couple lights on on the dash, engine and battery, but this thread will be about battery light. (not worried about engine light)

So it first came on when I spun the tires for a good few seconds trying to keep up with a friends subaru.... the light was not on before this.

Things I've checked:

-Battery voltage is 12.55 v. and it keeps going back to this, (I assume the alt is still working, just not to spec?)

-Battery voltage with engine on and all accessories off, goes down to 12.30 v. (I know this should be more.)

-Pulled ECU fuse (still good)
-Pulled ALT fuse (still good)


I'm going to check for continuity from the battery + terminal and BAT connection on the ALT, and also the - on the battery to the case of the Alt to check the ground.
I just want to be sure the alt is bad, instead of replacing it and finding out the problem still exists.


Anyone know what this problem is? or have any other ideas or suggestions?

thanks!

 

Check the connections at the alternator and fuse box.

 

Update:

Checked connections, they all look good, although I didn't take the fuse box off.

I do have continuity between ALT + and batt+ terminal
and ALT case to batt - terminal



Went to get groceries, and now it sits at 12.12v when engine on.

Battery light turns off at around 3300 rpm... ??

When testing with the engine running, higher rpm drops the voltage by .01v per second. And voltage dropped to 11.80v when the engine fan came on (idle).
Voltage did not increase at 3500rpm when the battery light turns off

Battery still sits at 12.55v when engine is off

any other ideas?

 

I don't think it has anything to do with the battery IMO

With my feeble mind (I am terrible with electricity), it sounds like the alternator is dead. Once the rpms go up to a certain speed, the alternator becomes efficient enough to have that light shut off.

 

This^

 

Check that the alternator belt is intact. If the alternator is spinning but the light stays on, that generally means that the alternator is bad.

 

Thanks for the replies guys,

The alternator belt is fine, and it is also tight.... just seems odd that it died in the middle of what was basically a burnout.

I'll look this over again tomorrow to be sure, and also unplug everything and plug it all back in. Just to be sure.

If I don't come across any more things to check, I'll put in a new alternator within the week.

I also joined another forum and the one guy has the same exact problem, the only thing is that it doesn't let me post there...


I'm still up for any more suggestions if anyone has any

 

Not sure how you think this couldn't happen. When you burn out and do that reckless ****, the entire car sees additional stress. In terms of the alternator, it experiences ALOT more vibration. Things are more prone to fail when driving the car hard. That should have been common sense

 

I meant frying the thing, Its obvious things could shake loose, and that's what I originally thought... but all of the connections seem good, and its still charging enough to allow me to drive around. Maybe it broke a connection inside the alt.

 

New alternator is in.
Charging at over 14v.

Job was less than 3 hours in my apt parking lot, all you need is a socket set.