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Battery light stays on


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20 replies to this topic

#1 HATCHY

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Posted 12 October 2012 - 06:54 PM

My hatch battery light is staying on. Im 100 percent sure my alternator and my battery are good, because I took them out of my daily driver hatch, I put it in my other hatch , and battery light is on, I checked all grounds and battery terminals, and alternator wires, coil, everything, I cant get it to turn off. I ddrove it ten miles no problem, I noticed that thye lights arent get brighter with higher rev .which usually means the battery is getting juice. Im not sure if my hatch has a voltage regulator? Anybody have any ideas. 87 htachback

#2 edrach

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Posted 12 October 2012 - 08:29 PM

What year hatch? Sounds like a bad alternator to me; you moved the parts around and still have the problem. Have you checked the voltage on the battery with a meter? Both at idle and around 3000 rpm; that'll tell you whether the alternator is putting out or not.

#3 HATCHY

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Posted 14 October 2012 - 03:06 PM

its an 87 standard hatch. ea81. he battery is brand new marine battery, and the alernator is two month old brand new. and today when i went out there, all the lights on the dash are staying on, stomp lamp, parking brake, oil, brake fluid. then when i pull the charge fuse out of the box all lights turn off on dash , but car runs still. so wierd? ill have to check the battery i guess,

#4 Cougar

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Posted 14 October 2012 - 03:11 PM

From what you stated it sounds like either the alternator is at fault, or the external voltage regulator if your model has one. I suspect it does since it is a EA-81. If you do have an external regulator then I would suspect it is causing the trouble before the alternator. The battery is most likely okay. A faulty battery can't make the warning lights stay on when the ignition switch is turned OFF but a faulty external regulator sure can. The warning lights are tied to the alternator field circuit so they can be tested when the ignition is turned on and engine isn't running. When the engine and alternator are running normally then a ground for the warning lights circuit is removed and they turn off.

Edited by Cougar, 14 October 2012 - 03:21 PM.


#5 Gloyale

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Posted 14 October 2012 - 03:34 PM

red/white wire from alt to the charge light has a fault.

#6 HATCHY

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Posted 14 October 2012 - 04:18 PM

im not sure i have even seen the voltage regulator, wouild that be a little box on the fender area? If so I do not have one. I have fusable link box which the harness runs off.

#7 Cougar

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Posted 14 October 2012 - 07:21 PM

I don't see how the warning lights can stay on while the ignition is turned off unless there is a problem with the ignition switch itself. Power to the alternator should turn off with the ignition switch. There might be a backfeed issue from the main connection to the alternator but then you say the alternator works ok in the other car.

I don't have service data for your model. There may be a blocking diode inside the cluster that has shorted and it is allowing power from the fuse to backfeed to the lights. You could try placing a diode in series with the fuse and installed so that is blocking current coming from the fuse and goes to the cluster (arrow points to the fuse). If that makes the lights turn off then the diode in the cluster is shorted and allowing power to backfeed to the lights. Using something like a 1N4001 diode should work ok if you want to try that.

Edited by Cougar, 14 October 2012 - 08:16 PM.


#8 HATCHY

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Posted 14 October 2012 - 08:04 PM

not ignition fuse. that kills the car. Its the. 10 amp fuse that says charge. some weird stuff.

#9 soobiefreak85

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Posted 14 October 2012 - 08:36 PM

Hey man,

Had the same problem with my 87 hatch. Battery was good, wires and fuses were good. After some tests, I replaced the alternator. The internal voltage regulator was the cause, I believe.

I believe 84 was the last of the external voltage regulator. Someone correct me if I am wrong.

Check your grounds! The block, body...everywhere! I have had several issues with grounds on mine. It doesn't hurt to have extra wires tracing to the body to ensure the grounds are well established if they are in question.

Throw a meter on the battery while it is running, as you accelerate the voltage should increase. If not, there is something at fault. If fuses are good and no wires are shorting, then what else could it be? I would replace the alternator. Good luck bro.

Wes

#10 djellum

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Posted 14 October 2012 - 09:30 PM

I had the same thing happen for about 15 minutes after I powerwashed the engine bay. the were all staying on while I was driving, though the car drove just fine. as i was going down the road they got dimmer and dimmer and finally shut off. now they work as normal.

for me it was probably just some water causeing a connection somewhere that eventually dried out or blew out from the wind.

check your connections, make sure they are not loose and are clean. it may just be a back connect somewhere.

#11 Cougar

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Posted 15 October 2012 - 12:39 AM

not ignition fuse. that kills the car. Its the. 10 amp fuse that says charge. some weird stuff.


Yes, I realize that. You need to understand how the warning lights are tied into the dash so they do there job along with being able to go into the test mode when you turn the ignition on.

Lets check to see if the current path for the lights is going through the alternator. With the ignition OFF disconnect the small plug on the rear side of the alternator and then see if the lights go out. If they do turn off then the alternator is somehow making a path for the lights to turn on. I would assume that the alternator is backfeeding voltage to them if that is the case. With the plug back on the alternator see if you have voltage on the white/red wire using ground as your reference. If you do have 12 volts there then the alternator is backfeeding voltage to the lights and a blocking diode in the cluster may be shorted. If you see near zero volts then the alternator is completing a ground which is normal and power to the lights is coming from somewhere else. If the lights remain on when you disconnect the plug then see if the w/r wire has a connection to ground.

Edited by Cougar, 15 October 2012 - 12:51 AM.


#12 HATCHY

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Posted 15 October 2012 - 07:32 AM

thanks forbthe tips im going to dig out the circuit tester and try it out. appreciate. it hope this is is an easy fix

#13 Gloyale

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Posted 15 October 2012 - 12:10 PM

Test the Circuit this way.

Disconnect the "T" shaped connector, then with the engine running, apply 12v to the White/Red wire in the connector.

The Charge lights should now be off.

Light goes out = fault in Alternator.

Light stays on = Problem in circuit



Your hatch does not have an external VR. Last year for that was 81.

Edited by Gloyale, 15 October 2012 - 12:13 PM.


#14 rdweninger

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Posted 15 October 2012 - 12:10 PM

Hey Gloyale,
there's a fault in your post. The guy is trying to diagnose an electrical problem. Some genuine insight and advice would be appreciate. Genuine is the key word.
What's the fault in the red/white wire? Are you talking about volts, grounds, breaks, burns, resistance, flowers? An explanation of what you think the problem may be, and possible solutions or things to check is what this forum is about.
Thanks for listening. RW.

#15 edrach

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Posted 15 October 2012 - 07:21 PM

Hey Gloyale,
there's a fault in your post. The guy is trying to diagnose an electrical problem. Some genuine insight and advice would be appreciate. Genuine is the key word.
What's the fault in the red/white wire? Are you talking about volts, grounds, breaks, burns, resistance, flowers? An explanation of what you think the problem may be, and possible solutions or things to check is what this forum is about.
Thanks for listening. RW.

Sorry, I have to take issue with you on this. Gloyale's suggestion is right on by isolating the problem into one of two areas. Once that's done, further troubleshooting in the problem area makes sense.

#16 Cougar

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Posted 15 October 2012 - 07:40 PM

It's a little mysterious why the warning lights are staying on when the ignition is turned OFF. Power should not getting to them and that is why I suspect a back feed problem due to a bad blocking diode.

#17 HATCHY

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Posted 16 October 2012 - 12:23 PM

Ok first off. Cougar. When i pull ignition fuse the whole car shuts down i was talking about the charge fuse. Second all warning lights are now off. It was a faulty crimp job on my part at the back of the alternator. Now the battery lights and warning lights are all off. But the headlights dont get brigjter with revs. Which makes me a little suspicios. But it says it charging. According to the dash. Lol. Thanks for the help. Im still gping to run the circut tester to be sure. Thanks fellas

#18 Gloyale

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Posted 16 October 2012 - 02:55 PM

Now the battery lights and warning lights are all off. But the headlights dont get brigjter with revs. Which makes me a little suspicios. But it says it charging. ......Thanks fellas


Lights only get brighter with revs, if you have low volts at idle, or high load on the circuit at idle. If your alt does this it's probably wearing out, or there is a high resistance in the charge wire.

If they are bright all the time, and it starts every morning, things are good.

#19 Cougar

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Posted 16 October 2012 - 04:32 PM

Good deal, you found the problem. When you talk about using a circuit tester I assume you mean voltmeter. If the alternator can sustain a voltage between 13.8 to 14.8 volts while the engine is running around 1,500 RPM and there is a pretty good load on the system then you are good to go. If the alternator has less than a 13.5 volt output then some of the diodes inside it may be bad.

Edited by Cougar, 16 October 2012 - 04:36 PM.


#20 rdweninger

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Posted 16 October 2012 - 05:25 PM

edrach,
my post was in response to gloyales post from 10/14 at 1:34 pm where he simply stated you had a fault in the red/white wire.
Today, when looking at the last posts, both mine and gloyales 2nd post have exactly the same time. So while I was writing my repsonse, gloyale must have been getting telepathic messages from me and wrote his 2nd (more descriptive) post.
my apologies to both you and gloyale.
but you gotta admit the telepathy is pretty cool. RW.

#21 edrach

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Posted 16 October 2012 - 07:36 PM

edrach,
my post was in response to gloyales post from 10/14 at 1:34 pm where he simply stated you had a fault in the red/white wire.
Today, when looking at the last posts, both mine and gloyales 2nd post have exactly the same time. So while I was writing my repsonse, gloyale must have been getting telepathic messages from me and wrote his 2nd (more descriptive) post.
my apologies to both you and gloyale.
but you gotta admit the telepathy is pretty cool. RW.

Apology not needed, but appreciated. Thank you. I didn't mean to curtail what you post. I like this board because people don't flame or get flamed.




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