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I have a 87 hatch, I'm havingb issues with my charging I'm only getting 12.3volts. I've checked and went through all my grounds and tried two different alternators and batterys. That I know are good. And the other issue all my dash lights stay on . Egr stomp lamp parking break brake fluid etc. This happened by itself . I parked the car for 6 months and then fired it up

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Pretty sure burned out battery bulb wouldn't cause the car to not charge. I dint believe I even have a voltage regulator either. The 78 brat has one and the 81 wagon . But 85brat doesn't. And my standard I don't think has one either. Pissing me off I'm ready to drive it again.

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87 is internally regulated, batt bulb is in the dash right above the voltage gauge and its a good place to start.

Edited by mikaleda

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i would say if he's not seeing the bulb light up than that would be a good place to start, if the bulb is not burned out then he is probably not getting power to the "feild current" wire on his alt. it could be the resistor also.

 

Question for the op, when you turn your key to on do you see the battery light light up?

Edited by mikaleda

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My lights don't get brighter when I step on gas. And rpm doesmt change the battery light either. Isnt the refulator and resistor built in. Cause it did it with a brand new alt

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87 has internal regulator but, the resistor is part of the charge light setup, but if you are seeing the light one before you start it and the it turns off when your running your problem would be in either the sense wire, or the main charge lead.

Edited by mikaleda

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If the car sat for 6 months like you said.... a battery with a dead cell can cause funky things to happen with your alternator.  Try to pull a good battery from your other vehicle (or a friends) and see what happens.  

Do you have a volt meter?

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Yes I've tried three batterys and yes I have volt meter that's hiw I know I was only getting 12 volt charge. And yes my oil lamp and battery lamp come in when my ignition is on. I have by passed my igntion for push button start like 8 years ago. Never had a priblem with charge. I have to plug my car into a plug in the back of the column. I've went through all the wires and soldered them for longevity. So baffling. Terminals tight all wires into the terminal tight. My car doesnt have voltage regulator or anything.... . . . . Dangit

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sounds like your internal voltage regulator is failing , check for AC voltage , if you have ac voltage , replace the alternator .

Edited by ivantruckman

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hmmm... well if the battery light is turning on with the ignition on than your problems down the line somewhere. there are a couple possibility's if the light is turning off when the engine is running than i would run a jumper between the batt post and batt positive and see if that makes the output better. you could check for ac ripple but, that has to do with the alternator itself so that wouldnt have followed with new alts.

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It is important that the battery warning light works because the field windings of the alternator are powered though that lamp. Does the battery warning light turn OFF, like it should do, when the engine is running? If it doesn't you may have a ground problem on that lead. If you disconnect the plug on the back side of the alternator the warning light should not turn on if you start the car up. If it does turn on then there is a ground on that lead that needs to be removed.

 

There should be two leads on the back side of the alternator and both of those leads should be close to battery voltage if things are good with the engine running. Another lead to check is the main output lead of the alternator. Is that where you made your previous tests at or was it the battery posts? If you checked the battery then check the main output lead using ground as your reference. The difference between the battery and the alternator output voltages should be very little. You can also check the voltage drop across the lead while there is a good load on the system. Place the red probe on the alternator output and the black probe on the positive battery post. You should have less than .5 volts on the lead if the connection is good. 

 

You stated that other warning lights are on so there is some concern there may be a problem in the cluster. Perhaps the field wire has a ground on it. I think it is blk/wht wire.

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The easiest "trade tree mechanic" trick to test for a bad alternator or generator is to remove the negative battery strap once the car is running.  If the the engine dies, you have a bad alternator/generator.  If it stays running you probably have a crappy battery or a bad wire somewhere.

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That method warked okay back in the day but shouldn't be used considering the electronics that is used in todays cars.

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The easiest "trade tree mechanic" trick to test for a bad alternator or generator is to remove the negative battery strap once the car is running.  If the the engine dies, you have a bad alternator/generator.  If it stays running you probably have a crappy battery or a bad wire somewhere.

Not realy that accurate though. I am a shadetree mechanic and I use a multi meter, in most ways it's actually easier that disconnecting the battery cable.

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it will not show you a overcharging alt witch is the most commen failure have seen them hit 20 volts muti meter +1 should be 14.20 -14.0 volts no higher and no lower than 13.0 at 3000rpms

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My car did not cone with tach. Hahah I diid disconnect battrty whule the car was running. It shut down. So ikk try a new alty again and see . Still getting 12 volts. Thanks fir all the help. Ill keep chipping away

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