Red battery light
#1
Senior Member
Thread Starter
Red battery light
I tried searching about this but did not find anything relevant. Creating the thread for research and future reference.
Short story: Wife drove the truck to the store (less than a mile from home). Said (red) battery light came on on the dash, and shortly after, ABS light. After the store she could not start the car (would not crank). Left the truck on the parking lot and walked home. After work I took the battery/starter and drove over to the store's parking lot. Hooked up the battery booster and started right up. While driving home, abs, esp, srs light were on and off. Water temp light came on, cruise control not working. Seemed like truck was driving in a low range gears mode. Radar detector displayed "low vot". It did that on a different vehicle when battery was low/dead.
Troubleshooting: Checked the alternator belt, its still there, so the alternator is spinning. Charged the battery on "fast" mode for couple of hours. Started the vehicle without any issues. After a few minutes of idling, battery light came on again. Shut it down and it did not start again without a battery booster. Checked the battery voltage, it was below 11v. Checked the voltage with engine running, same 11v. Bad alternator? At this point, charging a battery to a full charge on "slow" charge. So far it was charging for 8 hours or so. Usually my other batteries would be fully charged by this time. Bad alternator and bad battery?
Short story: Wife drove the truck to the store (less than a mile from home). Said (red) battery light came on on the dash, and shortly after, ABS light. After the store she could not start the car (would not crank). Left the truck on the parking lot and walked home. After work I took the battery/starter and drove over to the store's parking lot. Hooked up the battery booster and started right up. While driving home, abs, esp, srs light were on and off. Water temp light came on, cruise control not working. Seemed like truck was driving in a low range gears mode. Radar detector displayed "low vot". It did that on a different vehicle when battery was low/dead.
Troubleshooting: Checked the alternator belt, its still there, so the alternator is spinning. Charged the battery on "fast" mode for couple of hours. Started the vehicle without any issues. After a few minutes of idling, battery light came on again. Shut it down and it did not start again without a battery booster. Checked the battery voltage, it was below 11v. Checked the voltage with engine running, same 11v. Bad alternator? At this point, charging a battery to a full charge on "slow" charge. So far it was charging for 8 hours or so. Usually my other batteries would be fully charged by this time. Bad alternator and bad battery?
#2
go to engineering menu. display is set to voltage. you should read 12.4 - 12.7 with engine not running. fire up engine. does voltage go up?
yes - battery is bad.
no - alternator is suspect.
yes - battery is bad.
no - alternator is suspect.
#4
#5
Super Member
When you push the 'R' button you may have to experiment with how fast you push. The first few time I did it (to get to the menu to tell the computer I had changer the oil) I pushed too slow -- it didn't respond. My guess is about 3 times in 2 seconds works.
OR - if you have a voltmeter, hook it up to the jumper terminals under the hood, start the car and read the voltage. It should read about 14V on a fully charged battery, less if the battery is down. If the alternator isn't putting out, voltage of 11 or less in not unheard of. If it gets below 10.5V the computer refuses to operate and you will probably lose all data saved in the NAV system.
OR - if you have a voltmeter, hook it up to the jumper terminals under the hood, start the car and read the voltage. It should read about 14V on a fully charged battery, less if the battery is down. If the alternator isn't putting out, voltage of 11 or less in not unheard of. If it gets below 10.5V the computer refuses to operate and you will probably lose all data saved in the NAV system.
#6
Senior Member
Thread Starter
Confirmed. After charging the battery to full capacity. Voltage does not go up while engine is running. On the menu or with volt meter.
Should I start removing the alternator? Getting it checked and (more likely) replace it with a new one?
Should I start removing the alternator? Getting it checked and (more likely) replace it with a new one?
#7
That would be my next step...
Take it to your local autozone - they can test it for you. There are other simple field tests , but the simplest is to take it to have it tested.
Take it to your local autozone - they can test it for you. There are other simple field tests , but the simplest is to take it to have it tested.
Trending Topics
#10
regarding alternator fuse - good question. will not hurt to run quickly through all the fuses with an ohm meter anyway...
#11
Senior Member
Thread Starter
Took the alternator to the alternator rebuild shop to do the test. They put it on the alternator dyno machine and told me that as soon as they give it some load, "it drops". I'm still not exactly sure if voltage drops or what, but technician will take a look at it to tell me what exactly wrong with it.
#15
Senior Member
Thread Starter
I did not buy a new one. Mine was rebuilt with new parts. But I think new one is ~$400 My alternator is located on the passenger side, towards the bottom of the engine. Removing it was not too difficult, putting it back was little harder. Alternator is not light weight and there isn't much room to work. My right hand was all scratched up. Looked like I was depressed and cutting myself lol. If I'd have to do it all over again, removal and installation would take me about 1 hour. Because you also need to remove some intercooler houses and serpentine belt. I also replaced that belt with a new one. I hope this helps.
#16
Member
Reviving an old thread. While in stop-and-go traffic this morning on slippery roads (with ABS engaging several times), the red battery light came on. I'll go ahead and try the suggestions mentioned above.
I'm not sure if it's related, but 2 days ago, the "ESP Inoperative" message came on randomly. It has since turned off after shutting down the car for a couple hours and restarting again.
Thanks much in advance for any suggestions.
I'm not sure if it's related, but 2 days ago, the "ESP Inoperative" message came on randomly. It has since turned off after shutting down the car for a couple hours and restarting again.
Thanks much in advance for any suggestions.
#17
Member
Voltage after starting.
I used the engineering menu to determine battery voltages after a couple hours. The red light seems to be gone for now, thankfully. Perhaps it was the ABS constantly turning on/off this morning due to slippery conditions.
Voltage before starting.
Last edited by Isentropic; 01-09-2018 at 03:10 PM.
#18
Member
I went off-roading couple weeks ago, and the red battery light came on again. Not sure what's going on.
Recently, the "Gas Cap Open" message also appears. Could they all be related? Perhaps a faulty alternator/battery causing electrical glitches?
Check engine light is also on.
Any help would be greatly appreciated.
Recently, the "Gas Cap Open" message also appears. Could they all be related? Perhaps a faulty alternator/battery causing electrical glitches?
Check engine light is also on.
Any help would be greatly appreciated.
#19
MBWorld Fanatic!
I wouldn't think the emissions is related to a battery or alternator. But, is your gas cap actually open? If not, probably just time to replace it.
You never mentioned what your battery voltage was after the car sat for a few hours and also while running? Note whether the battery light is illuminated during this. Or, just use a DVM.
Just a guess, but the first thing I think of is a loose/dirty connection somewhere amongst the alternator/battery system, since it seems to be happening intermittingly - or at least that's a good place to start since it's a "freebie" fix if it's the issue... and always a good place to start with electrical gremlins.
How old is the battery?
You never mentioned what your battery voltage was after the car sat for a few hours and also while running? Note whether the battery light is illuminated during this. Or, just use a DVM.
Just a guess, but the first thing I think of is a loose/dirty connection somewhere amongst the alternator/battery system, since it seems to be happening intermittingly - or at least that's a good place to start since it's a "freebie" fix if it's the issue... and always a good place to start with electrical gremlins.
How old is the battery?
#20
Member
Thanks much for the insights. I’ve been checking the battery voltage for the past two days, and it seems to be hovering around 11.6 V and 11.7 V when the car is not running. Once the vehicle is started up, the voltage jumps to around 13.7 V. Does this seem normal? Thanks so much again.
#21
MBWorld Fanatic!
Ah, some data!
A good battery will show mid to upper 12-volt range. 11.7 is too low. 13.7 when running means the alternator is good... assuming you've checked the battery/alternator cables. It's possible to show 13.7V, but not be passing enough amps.
With the new "data", though, signs point to a bad battery (again, on the "assumption" from above). How old is the battery? The intermittent thing could be explained by the battery being on the fringe and the alternator not always able to keep up. It will get worse - fix it before you get stranded.
A good battery will show mid to upper 12-volt range. 11.7 is too low. 13.7 when running means the alternator is good... assuming you've checked the battery/alternator cables. It's possible to show 13.7V, but not be passing enough amps.
With the new "data", though, signs point to a bad battery (again, on the "assumption" from above). How old is the battery? The intermittent thing could be explained by the battery being on the fringe and the alternator not always able to keep up. It will get worse - fix it before you get stranded.
#22
Member
Ah, some data!
A good battery will show mid to upper 12-volt range. 11.7 is too low. 13.7 when running means the alternator is good... assuming you've checked the battery/alternator cables. It's possible to show 13.7V, but not be passing enough amps.
With the new "data", though, signs point to a bad battery (again, on the "assumption" from above). How old is the battery? The intermittent thing could be explained by the battery being on the fringe and the alternator not always able to keep up. It will get worse - fix it before you get stranded.
A good battery will show mid to upper 12-volt range. 11.7 is too low. 13.7 when running means the alternator is good... assuming you've checked the battery/alternator cables. It's possible to show 13.7V, but not be passing enough amps.
With the new "data", though, signs point to a bad battery (again, on the "assumption" from above). How old is the battery? The intermittent thing could be explained by the battery being on the fringe and the alternator not always able to keep up. It will get worse - fix it before you get stranded.
I was driving on the freeway and suddenly the entire car just shut-off and turned back on, all in one sec. I heard a thump too.
I was very startled, especially at such a high speed. Since I have KEYLESS GO, I don't think it's due to the physical key losing contact with the ignition (since it's obviously not even plugged in). Could it be due to the dying battery? Has this situation happened to anyone?
Just bought a replacement battery on Advance Auto Parts (AGM type), and will see if I can change it myself.
Thanks much again.
I was very startled, especially at such a high speed. Since I have KEYLESS GO, I don't think it's due to the physical key losing contact with the ignition (since it's obviously not even plugged in). Could it be due to the dying battery? Has this situation happened to anyone?
Just bought a replacement battery on Advance Auto Parts (AGM type), and will see if I can change it myself.
Thanks much again.
Last edited by Isentropic; 04-18-2018 at 09:39 PM.
#23
A bit worrisome
Thanks much for the suggestion. A VERY SCARY thing happened today:
I was driving on the freeway and suddenly the entire car just shut-off and turned back on, all in one sec. I heard a thump too.
I was very startled, especially at such a high speed. Since I have KEYLESS GO, I don't think it's due to the physical key losing contact with the ignition (since it's obviously not even plugged in). Could it be due to the dying battery? Has this situation happened to anyone?
Just bought a replacement battery on Advance Auto Parts (AGM type), and will see if I can change it myself.
Thanks much again.
I was very startled, especially at such a high speed. Since I have KEYLESS GO, I don't think it's due to the physical key losing contact with the ignition (since it's obviously not even plugged in). Could it be due to the dying battery? Has this situation happened to anyone?
Just bought a replacement battery on Advance Auto Parts (AGM type), and will see if I can change it myself.
Thanks much again.
#24
Member
Thanks much for the suggestion. A VERY SCARY thing happened today:
I was driving on the freeway and suddenly the entire car just shut-off and turned back on, all in one sec. I heard a thump too.
I was very startled, especially at such a high speed. Since I have KEYLESS GO, I don't think it's due to the physical key losing contact with the ignition (since it's obviously not even plugged in). Could it be due to the dying battery? Has this situation happened to anyone?
Just bought a replacement battery on Advance Auto Parts (AGM type), and will see if I can change it myself.
Thanks much again.
I was very startled, especially at such a high speed. Since I have KEYLESS GO, I don't think it's due to the physical key losing contact with the ignition (since it's obviously not even plugged in). Could it be due to the dying battery? Has this situation happened to anyone?
Just bought a replacement battery on Advance Auto Parts (AGM type), and will see if I can change it myself.
Thanks much again.
#25
Getting that battery out
The battery is a vicious beast. I used a heavy pry bar with a curved end. I pry the battery up enough to get a long, flat, sturdy bar wedged just a millimeter under the bottom and then yank it up, sliding it up the bar (I actually used a piece of oak 1x2 with a wedged end) and out. Not 5 seconds out, but you can get it out if you can just get something under it.