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Lee
Lee, ASE Certified Technician
Category: Buick
Satisfied Customers: 395
Experience:  31 years experience ASE Master Technician
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1997 buick century: charging..battery and alternator..battery light

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1997 buick century, charging ststem nor working, battery and alternator replaced, still getting battery light and battery discharging???
Hi! There

Check the 10 amp Gen Fuse in the underhood electrical center.

Lee
Customer: replied 7 years ago.

Hi,

Fuse is OK.

Has the RED and the ORG wires at the alt. have battery voltage on them?
Customer: replied 7 years ago.

ORG does, RED doesn't, I'm only have a test light handy to check them.

 

Your problem is a blown fusable link at the starter solenoid.
Customer: replied 7 years ago.
Can it be replaced, or new solenoid? Can you give me an idea what it looks like?
You replace the fuse link. It is on the large termnel on the starter solenoid. It looks like a wire. You will problelly have the large wire from the battery and 2 or 3 smaller wires. the smaller wires are fuse links. Using your finger, pull on each one of them. The bad one will strech. The good ones will be solid. Sometime they will completelly burn into, but most of the time just the inside burns apart leaving the case in tack.
Customer: replied 7 years ago.

Found two fuseable links, both seem to be good. I have juice at both ends of both of them.

You should have power at the red wire. Did you check the big red wire or the small red wire at the alt.? The bigger one is feed by the fuse link. If you do not have power there and the fuse link is good Then the wire must be broken between the fuse link and the alt. This would be very rare. Double check the red wire for power.
Here is the wiring for that car
graphic
Customer: replied 7 years ago.

I checked the small red wire. The big red wire has power.

SORRY my fault, I did not say big or small. OK! the fuse link is good. Check to make sure the alt. is grounded. Put one end of the test light on the big red wire and the other end on the alt. case. It should light up. Next you will need a voltmeter. unplug the alt. connector turn key to run, check for voltage on the small red wire.
Customer: replied 7 years ago.
Alternator is grounded, but i don't have a voltmeter. Anything else I can try tonight?
You need a voltmeter for the other checks.
Customer: replied 7 years ago.
Is there any way i can get back with you tomorrow? Do you have a ideas of the likely cause?
YES! I am normally on between 5:30 and 9:00 pm est. sometimes earlier and most of the time later. Just respond through this question. It is starting to look like a ECM. If it is we may be able to bypass it.
Have you got a volt meter, so we can finish checking the car.

Lee
Customer: replied 7 years ago.

Hi Lee,

I just got home and checked the small red wire like you told me. Its showing right around 4 volts.

Ok check the gray wire. Key on engine running. What is the volt reading?. Also before cranking put meter on battery and get a battery reading. With everything hooked up ans engine running what is the battery reading.
Customer: replied 7 years ago.


Gray wire, engine running.042

battery , engine not running 12.75

battery with engine running12.15

Voltage on small red wire with engine running and everything hook up? This is the last voltage check.
Customer: replied 7 years ago.
Its hovering around .25 and the battery light came on.
Ok! The field wire is not being excited by the ECM. There for a no charge condition. The gray wire should have battery volts, supplied by the ECM. This can be checked by putting a volt meter on the battery. unpluging the alt. connector. Jump battery voltage from the big red wire to the org. and grey wire termanals on alt. Look at volt meter it will read 13.5 to 14.75. If so you have a bad ECM. The ECM can be bypassed, but it will not cause the battery light to go off, because the ECM controlls the light. If you do this jump use care not to short anything.
Customer: replied 7 years ago.
Its going to be very difficult to get a jumper wire on the org and gray terminals on alternator since the plug faces the firewall and I cant see in there. could I cut the orange and gray wires and still use the plug to try it? Is that the way to bypass the ECM if thats the problem, I don't really care about the battery light as long as its charging and not draining battery. I'm afraid if I try to just go to the terminals on the alternator, I'll short something.
Cut the gray wire and put battery volts on it. it should charge. Check and make sure you have 13.5 to 14.75 volts at battery. To bypass it run the gray wire from alt. to a key on power. This bypasses the ECM. A good key on power would be the yellow wire going to the wiper motor.
Customer: replied 7 years ago.

OK, I connected gray wire to large red wire at alterantor and battery showed 14.5 volts. HURRAY!!!!So, I just hafta connect the gray wire to yellow windshield wiper wire, correct? Where is the easiest place to find the windshield wiper wire, will I need to get under cowling where windshield wiper motor is?

Would it be possible to pick up a new ECM at a junkyard? Is it likely I'll have other problems with ECM?

You don't have to hook it to the yellow wiper wire. Any good key on power will work (KEY ON power). I just figured the yellow wire would be easy to get to. A junk yard ECM will not be programed with your vin. but will work as long as it is EXACTLLY the car and options. The vin problem comes in if you live in a emission state. As far as problems with ECM, I could not give a true answer. The circuit in the ECM problelly burn because of a bad alt. and no other circuit was affected, but I can not confirm that.
Lee and 2 other Buick Specialists are ready to help you
Customer: replied 7 years ago.

Thank you very much, Lee, you really know your stuff, mechanical I can handle, but the electical systems are over my head.. I've been layed off all year and you saved me that $75 an hour mechanic's fee. I really can't thank you enough.

Thanks again,

Ken

You are welcome. Thank You for using just answers.

Lee