Battery Light Refuses to turn off

[Storm897]

Car is a 2001 Honda Civic 2DR EX Coupe.

First let me prefix this by saying I have already searched and read every thread in regards to the Battery Light staying on.

I took my car to my mechanic and he first tried to turn if off but could not.

I then took it to Hersons Honda who also cant seem to figure out this **** Battery Light problem.

First let me explain what we have tried:
1.) Checked the volts on the alternator and there are fine. They measure 14-14.2 Volts. This was measured by both the Honda tech and my mechanic.
2.) Battery was replaced twice. I replaced it 3 weeks ago first. Then on Sunday I went back to Advance auto parts to change it again just in case something was wrong with it.
3.) We checked every single fuse under the dase and under the hood and there ok.
4.) We checked for bad grounds and can’t seem to find any.
5.) Alternator Belt is not loose. It is on tight. Alternator belt/power steering belt/timing belt where changed in February and never had a problem.
6.) My mechanic took out the ECU Fuse under the hood, but the light came back on. Honda tried to reset it and they said the same thing.
7.) I even replace the alternator and the light still stays on.

Honda thinks it MIGHT be a problem with a short on a cable from the ECU to the Dash board, or the ECU to the alternator or battery.

I think there just fishing for answers because they have no clue what’s wrong with it. They said they would have to pull the dash apart and checking the above recommendation would cost $350.

I told them no way.

I also ran the OBD Reader but no codes were returned. I just did this for good measure as there was no check engine light anyways but i wanted to be sure.

What could it be?

Thanks again in advance.

Oren

Here is the diagnoses from the previous alternator (now replaced with a new one).
It has the battery test and alternator included.

 

[Hootbro]

Delete

 

[Hootbro]

Sounds like a short. Does the ecu supply a ground or voltage power to trip the light? Had a like problem with an airbag light on a Nissan PU. Looks like you wasted a bunch of money on this one.

Hootbro

 

[Schmoe]

If all else spec's out, something is telling the "brain" that there is something wrong. Boy, I wouldn't know where to start on the Honda's.

 

[brianl703]

Find a wiring diagram. Find out what it si that the the battery light eventually connects to. (On many cars, it connects to the voltage regulator). Disconnect it.

Did the light go out? If yes, the problem is something in the voltage regulator or whatever you just disconnected it from.

If no, then you have a short somewhere. Now you can start by disconnecting wiring harnesses between the battery light and what it connects to, until the light turns off.

$350 to rip the dash apart to find the cause of the problem? Good to see that the Honduh dealer is just as incompetent as the rest of them.

Bottom line: You need a wiring diagram to solve this problem. A multimeter and the knowledge of how to use it properly would help, too.

 

[brianl703]

The latest Honda service information I have access to is for 2000, but in 2000 the charging system indicator light is wired between fuse 24, a 15amp fuse, and the regulator in the alternator.

If your 2001 model is wired this way, a short to ground on the wire between the alternator and the indicator light would cause it to come on whenever the key is in run or start.

This could be verified by unplugging the connector from the alternator and turning the key to ON. If the light continues to stay on, you have a short somewhere. If not, the regulator is turning the light on for some reason. You will have to figure out why.

 

[Storm897]

quote:

---

Originally posted by Hootbro:
Sounds like a short. Does the ecu supply a ground or voltage power to trip the light? Had a like problem with an airbag light on a Nissan PU. Looks like you wasted a bunch of money on this one.

Hootbro

---

The tech from Honda said that most likely there’s a short in the line going from the ECU to my dash. I am not sure how correct he is though. They want to charge $350 to take apart my dash and trace some wires. If that is not it he said that I still have to pay the $350 because of the labor used to diagnose the problem.

 

[Storm897]

quote:

---

Originally posted by johnd:
It's a long shot but I have seen alternators with one diode out that would still keep the battery charged but the light would stay on. That was GM, Honda?

---

My car is a 2001 Honda Civic Ex. I have already replaced the battery and alternator and the light remains on.

 

[Storm897]

quote:

---

Originally posted by Quest:
several questions:

(1)Is the car completely stock? Did you add anything on this Civic (e.g. boombox, head unit, amps, security alarms, DVD players, etc.)?

(2)When did this happen precisely? Did the car experienced some sort of abnormaly when this first happened (lightning strike, etc.)?

(3)Has this car experienced some sort of shorts(electrical) all these years? (I'm thinking of an electrical spike here due to shorts)

---

1.) The car is completely stock.

2.) Before this light turned on, the alternator belt was making a weird noise (Saturday morning). I still drove it on Saturday because I couldn't take it to the mechanic right away. That night the battery light came. At 3 am Sunday morning I got stuck (while out with friends) because my car shut off while I was driving. I had it towed to my mechanic and he said my alternator belt bolt broke and he fixed it for me. Because the alternator wasn't providing energy and charging the battery, the card died. Ever since then the car runs fine. My only problem is that I can’t get the light to turn of.

The picture above was when the Honda Dealership tested the alternator after my mechanic fixed the bolt.

3.) Once before I had to replace a head light harness due to a recall on my civic. Other then that no electrical problems

 

[Storm897]

quote:

---

Originally posted by brianl703:
Find a wiring diagram. Find out what it si that the the battery light eventually connects to. (On many cars, it connects to the voltage regulator). Disconnect it.

Did the light go out? If yes, the problem is something in the voltage regulator or whatever you just disconnected it from.

If no, then you have a short somewhere. Now you can start by disconnecting wiring harnesses between the battery light and what it connects to, until the light turns off.

$350 to rip the dash apart to find the cause of the problem? Good to see that the Honduh dealer is just as incompetent as the rest of them.

Bottom line: You need a wiring diagram to solve this problem. A multimeter and the knowledge of how to use it properly would help, too.

---

quote:

---

Originally posted by brianl703:
The latest Honda service information I have access to is for 2000, but in 2000 the charging system indicator light is wired between fuse 24, a 15amp fuse, and the regulator in the alternator.

If your 2001 model is wired this way, a short to ground on the wire between the alternator and the indicator light would cause it to come on whenever the key is in run or start.

This could be verified by unplugging the connector from the alternator and turning the key to ON. If the light continues to stay on, you have a short somewhere. If not, the regulator is turning the light on for some reason. You will have to figure out why.

---

Great posts guys. Thanks a ton. Since my battery was only 3 weeks old, I replaced it with a new one from advance auto parts and tested the draw from the battery. It was .05 amps. So nothing is wrong from the battery point of view.

I will attempt to investigate what you guys said this Sunday. Hopefully I can find the culprit of this problem.

I have the 2500 page Honda manual that I will look through. I will post the electric diagram if I get stuck or confused.

P.S.
This week gets worse every day. Came back to put money in my parking meter today and was late by 9 minutes. Got a $30 ticket.
ARGH!!!!!

Thanks again guys.

 

[JHZR2]

I think youre making it up... maybe youre seeing things. Hondas are never supposed to have problems, especially when they are only 5 years old.

In my old mercedes, the battery and seatbelt light would come on intermittently because there was a grounding issue internal to the instrument cluster. You might have an issue in there.

JMH

 

[Axe Man]

I have the electrical manual for 2001 - 2004 Civic. The battery lamp circuit is horrendously complex. From the alternator to the ECU to a processor in the dash itself to the actual lamp. A real mess. The dealer stating that it's a possible problem in the dash might indeed be right.

I have the pages you need in PDF format. If you want them send me an e-mail at [email protected]

 

[brianl703]

There is a possibility that it's like a GM vehicle and the alternator light really is controlled by the ECU, either through a multiplexed data link (much like a LAN) to the instrument cluster or a direct connection to the ECU for the light.

IF that is the case though (I doubt it is--it would be a radical departure from how Honda usually approaches vehicle electronics), they should be able to use a scantool to command the alternator light on and off to see if it's responding properly to data commands from the ECU to make sure it's not "stuck on". If it were "stuck on", that would be a problem internal to the instrument cluster and generally those are not field-repairable so it would have to be replaced.

If the ECU were really commanding the light on, there should be a code in the ECU, which they can use a scantool to see, which tells them what the problem is.

EDIT: If it is indeed wired like a GM, any short in the connection between the ECU and the instrument cluster would affect a lot more than just the battery light...

 

[johnd]

It's a long shot but I have seen alternators with one diode out that would still keep the battery charged but the light would stay on. That was GM, Honda?

 

[Quest]

several questions:

(1)Is the car completely stock? Did you add anything on this Civic (e.g. boombox, head unit, amps, security alarms, DVD players, etc.)?

(2)When did this happen precisely? Did the car experienced some sort of abnormaly when this first happened (lightning strike, etc.)?

(3)Has this car experienced some sort of shorts(electrical) all these years? (I'm thinking of an electrical spike here due to shorts)

 

[Storm897]

Honda ran its scan tool as did I and so did my mechanic. No codes were returned.

I took out the ECU Fuse under the hood and put it back in after 10 minutes to reset the system. The battery light still came on right away.

 

[brianl703]

Have you priced out junkyard instrument clusters yet?

 

[eljefino]

I'm with axeman and brianl703. I don't know hondas per se but they seem to be moving this way these days. The latest GMs like my 99 intrigue have PCM/BCM controlled alternators that, for example, wait a second after you start the car before they gently start producing.

The older cars would cut out the field during crank then suddently put it back in when the motor started and key released to "run". The older cars, also, relied on the "battery" light to properly feed the alternator field. Except mopar stuff.

Mad though that it should throw a code or maybe a service wrench light (non-emissions failure that's seperate from the SES light.) This could be a manufaturer specific code that only the dealer can access... try a different honda dealer. Might be under a submenu of non-emissions problems for example that they glanced over.

I lost an alt, overvoltage situation, on a 99 hyundai and the airbag controller hated this. It remembered the code even after a night of disconnected battery, and proper alternator. Took a trip to a good dealer to cure this. Could be you have something "stuck" in some memory chip somewhere.

 

[Storm897]

quote:

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Originally posted by brianl703:
Have you priced out junkyard instrument clusters yet?

---

The image below is from Majestic Honda. (New)

I have tried 2 local junk yards but they dont have any civics 2001-2005 in there lots.

 

[Storm897]

quote:

---

Originally posted by eljefino:
I'm with axeman and brianl703. I don't know hondas per se but they seem to be moving this way these days. The latest GMs like my 99 intrigue have PCM/BCM controlled alternators that, for example, wait a second after you start the car before they gently start producing.

The older cars would cut out the field during crank then suddently put it back in when the motor started and key released to "run". The older cars, also, relied on the "battery" light to properly feed the alternator field. Except mopar stuff.

Mad though that it should throw a code or maybe a service wrench light (non-emissions failure that's seperate from the SES light.) This could be a manufaturer specific code that only the dealer can access... try a different honda dealer. Might be under a submenu of non-emissions problems for example that they glanced over.

I lost an alt, overvoltage situation, on a 99 hyundai and the airbag controller hated this. It remembered the code even after a night of disconnected battery, and proper alternator. Took a trip to a good dealer to cure this. Could be you have something "stuck" in some memory chip somewhere.

---

I tried using my $100 scanner and it returned no codes.

When Hersons Honda did there initial diagnoses, they used there scanner to reset my car and also found no codes.
Additionally, my mechanic checked and found no codes.

Its really weird. Must be something wrong electrically. Will have to spend a couple hours probably this weekend and figure it out. I can’t sleep comfortably knowing that the light is still on even if my car is running fine now.