Hyundai Forums banner

1 - 20 of 25 Posts

·
Registered
Joined
·
40 Posts
Discussion Starter #1
Hello all, hoping to find some advice on my 2012 GLS with 84,000 miles...

A few weeks ago I replaced a coil pack and all 4 plugs to correct a misfiring issue. Since then (perhaps coincidentally), the battery light will flash about once or twice a day. When it first happened, I stopped by a parts store to have the battery and alternator tested and they both passed. Battery is about a year old, terminal connections seem tight and there is no corrosion; battery is held down tight, not moving around. After a few days seeing it flash a few more times, I stopped by a different parts store to test again, and again both passed.

Last night, I noticed that the headlights were occasionally dimming, then brightening again.

Other than these issues, the car has no problem starting or driving. Is this a known issue to anyone? Or can anyone suggest a solution? My fear is all of the sudden being stranded somewhere.

Thanks in advance!
 

·
Registered
Joined
·
22 Posts
How's the serpentine belt, not loose is it? I had the light flash on my Accent when it was loose enough to slip at certain rpms or if I applied power swiftly. It wasn't always audible either when it happened, at least for me anyway.
 

·
Registered
2007 Honda CRV
Joined
·
4,582 Posts
Clean all battery connections and grounding points
Then take multi-meter (DVOM) and check the voltage across the battery with the engine running
Should be charging at around 14 to 15 volts
 

·
Registered
Joined
·
40 Posts
Discussion Starter #8
Thanks for the input everyone. I wire brush cleaned all the ground points this morning.

Serpentine belt looks good and only has about 1/8” deflection.

Battery shows 13.4v no power, 15v with the car on.

I’ll go driving and see if there’s any more issues and report back
 

·
Registered
Joined
·
40 Posts
Discussion Starter #9
unfortunatley, no luck - the battery light flashed again late last night. so now i guess it's either $125 for the dealer diagnosis...
 

·
Registered
2007 Honda CRV
Joined
·
4,582 Posts
Alternators sometimes use a signal from the ECU to determine the field strength
Which in turn determines the charging voltage or cureent
If the associated wiring is frayed or partially broken then it could make for an intermittent issue????


Note: This is sometimes .. something that can not be determined until powers and grounds are verified as good
 

·
Registered
Joined
·
505 Posts
I think 15v reading is just a tad high and maybe enough to trigger your batt light to turn on. Your alternator voltage regulator maybe on its way out. You should be between 13.5 - 14.5 volts only when engine is running.
 

·
Registered
Joined
·
17,552 Posts
Thanks for the input everyone. I wire brush cleaned all the ground points this morning.
Clarfify that ..

Serpentine belt looks good and only has about 1/8” deflection.

Battery shows 13.4v no power, 15v with the car on.
Then it charging, though 15V on UD/MD Elantra is a weee bit high,, expect to 14.2 nominal, and similar with loads on..

I’ll go driving and see if there’s any more issues and report back
I take and remove paint from under the lug to bare steel, slap some grease on metal, and re-attach power cable lug...... Again, as we all should know,, paint is an INSULATOR,,,,, not a CONDUCTOR...
 

·
Registered
Joined
·
40 Posts
Discussion Starter #13
I think 15v reading is just a tad high and maybe enough to trigger your batt light to turn on. Your alternator voltage regulator maybe on its way out. You should be between 13.5 - 14.5 volts only when engine is running.

the voltage reg is internal on these correct? i've been leaning this way since it's so inconsistent. i've seen reman alternators for about the same as the dealer service charge, maybe that's the way to go...
 

·
Registered
Joined
·
505 Posts
Yes its internal, you can even change that yourself if you can find a replacement. Its fairly easy to get to just a few small screws to remove on the back of the alt. I rebuilt a denso alternator for my other car 2 years back (changed the voltage regulator, brushes, rectifier and bearings) and its been running great since. Yup those reman alt from autozone with lifetime warranty is better money spent than dealer inspection charge. The good thing is the alt on these cars is right there in front of you and very easy access. Just like removing the battery.
 

·
Registered
Joined
·
785 Posts
Thanks for the input everyone. I wire brush cleaned all the ground points this morning.

Serpentine belt looks good and only has about 1/8” deflection.

Battery shows 13.4v no power, 15v with the car on.

I’ll go driving and see if there’s any more issues and report back
You should get a new multimeter. A fully charged lead acid won't read higher than 12.7volts.

The voltage regulator does vary the output voltage on these cars. Here's what I've found based on my experience

Battery not charging: output voltage is 12.5-12.7 (this is the output voltage of the car, i can't be entirely sure what the alternator is actually doing)
Headlights on: 14.1-14.2
Battery charging (headlights not on): 14-14.5

It makes life easy for you too if you get a voltimeter that plugs into your 12V accessory socket.
 

·
Registered
Joined
·
40 Posts
Discussion Starter #16
update - i installed the new alternator this morning. initial multimeter testing showed a more reasonable 14.5 when running. when i drive more over the next few days i'll better be able to say if this case is closed and i'll report back, but fingers crossed.
 

·
Registered
Joined
·
40 Posts
Discussion Starter #17
After a couple of days with no battery light I thought it was solved, and then it happened tonight...anything else you guys can think of?
 

·
Registered
Joined
·
40 Posts
Discussion Starter #18
Also, could a recently replaced coil pack have anything to do with it? I did replace th pack on cylinder 1 not too long ago
 

·
Registered
Joined
·
40 Posts
Discussion Starter #19
i replaced the serpentine belt for s&g, but the light is still flashing occasionally. someone suggested the cabling to the alt could be bad; he called it a "dyno cable", but i can't find anything like that online. anyone know what it's called? the wiring from the ecu not the battery.
 
1 - 20 of 25 Posts
Top