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Alternator not charging battery + other problems. HELP!

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Alternator not charging battery + other problems. HELP!

 
Old 04-08-2005, 10:17 PM
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kopbet89c4
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Default Alternator not charging battery + other problems. HELP!

Well, this is the problem. Ever since I got back from a local auto maintenance $hit shop (not my friend's shop) just for the diagnosis of my wiper hitting each other again, this stupid crap started happening. I had to wait for about 2 hours for them to diagnose it (replacing wiper transmission) and then I got back home. When I call them later and tell them what is going on, they deny that they touched the electrical system. WTF!!! First of all, now the battery light is on. So is the ABS light. Also, when the car is idling at 700 rpms, the alternator is making 14.5 volts when checked with my digital volt meter. Now when I check the battery voltage with the same volt meter, it is 10.0 volts (exactly the same on the dash). When the voltage is below 10, I won't be able to crank it. How the heck did this happen? Looks like I'll have to go through a disgustingly ill wiring mess here! I notice the car will eventually die if driving more than 15 minutes. I have a feeling the BBB might be involved since I think this is going to turn into a "he said, she said" debate between the dealership and this local $hit shop aka McGee tire in Lakeland. I promise I'll never go to any local roadside auto $hit shop again. Plus they have the exact same labor rate as the Chevy dealership here in Lakeland ($80/hr).
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Old 04-08-2005, 10:32 PM
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Your alternator clearly has no output. Charge your battery back up with a battery charger. Measure the voltage on the alternator output terminal with the engine running. If the alternator has no output, its output voltage should be identical to the battery terminal voltage which will be below 13 volts. If the alternator output terminal measures approx 14.7 volts but the battery terminal voltage measures much lower, like 12 volts, then the fusible link on its output wire has been blown and should be replaced. If your alternator has no output you can confirm a defective alternator by removing it and having it tested at an auto parts store (many will test your alternator for free).
It would be impossible to determine if the repair shop did anything to destroy the alternator but they could have momentarily shorted the battery or the alternator output and blew the alternator fusible link.
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Old 04-08-2005, 10:42 PM
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Originally Posted by jfb
Your alternator clearly has no output. Charge your battery back up with a battery charger. Measure the voltage on the alternator output terminal with the engine running. If the alternator has no output, its output voltage should be identical to the battery terminal voltage which will be below 13 volts. If the alternator output terminal measures approx 14.7 volts but the battery terminal voltage measures much lower, like 12 volts, then the fusible link on its output wire has been blown and should be replaced. If your alternator has no output you can confirm a defective alternator by removing it and having it tested at an auto parts store (many will test your alternator for free).
It would be impossible to determine if the repair shop did anything to destroy the alternator but they could have momentarily shorted the battery or the alternator output and blew the alternator fusible link.

First off, this alternator is 2500 miles new. Would you, by any chance, know where this alternator output fusible link is?

Need pics if possible. ASAP. I'm guessing that this is not that hard to fix if this is really the problem.

Last edited by xeugep; 04-08-2005 at 10:45 PM.
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Old 04-08-2005, 10:57 PM
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The large red wire on the alternator goes to the jump start bolt along with about 7 other red wires. You will have to follow the wire to find the fusible link. The link is a short section with heat shrink over it. You might remove the nut on the jump start bolt and pull on the alternator wire to determine which one is the alternator wire (disconnect the neg cable on the battery first).
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Old 04-09-2005, 12:05 AM
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Originally Posted by xeugep
Well, this is the problem. pen? Looks like I'll have to go through a disgustingly ill wiring mess here! I notice the car will eventually die if driving more than 15 minutes. I have a feeling the BBB might be involved since I think this is going to turn into a "he said, she said" debate between the dealership and this local $hit shop aka McGee tire in Lakeland. I promise I'll never go to any local roadside auto $hit shop again. Plus they have the exact same labor rate as the Chevy dealership here in Lakeland ($80/hr).
From painful experience, You may have a loose wire. Others have talked about the +12, i'll talk about the ground. The altenator, battery and starter all share the engine block as a ground (ei no other wires). Check the battery grounding bolt under the #7 exhaust.

The other thing maybe the battery connections are loose.

Tighten everything before you hit the BBB up
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Old 04-09-2005, 12:10 AM
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xeuqep, wait a minute.... when you saw 10V, was the engine running? and if you manage to get the engine started, does it still read above 14?

if so it could just be a bad battery that can't hold a charge.
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Old 04-09-2005, 12:25 AM
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Originally Posted by tempest
xeuqep, wait a minute.... when you saw 10V, was the engine running? and if you manage to get the engine started, does it still read above 14?

if so it could just be a bad battery that can't hold a charge.

Nah man, it will hold a charge, and when the engine is running, you will see the voltage drop 0.1 volt every minute and when the final voltage is below 7.5, it will just stall.

BTW, I tried wiggling around wires near the alternator so more than likely it could really be the fusible link that blew.

I might need a pic sooner or later to avoid the extra $80.00/hr diagnostic charge. I tried looking all around for the fusible link but I can seem to find it.
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Old 04-09-2005, 08:47 PM
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Default JFB's Battery Info

JFB - Thanks for the info on my battery, etc. I have not put a meter on it yet, but will tomorrow. I brought this 89 roadster from another town, 144 miles away. The previous owner had the Chevy dealer in Bradenton, FL put a new battery in the car. They did not check alternator output, as far as I know.
I took off, and about 30 miles out, the voltage on the dash kept going down. I kept watching it, and this is on a Saturday, and when I was 62 miles away from the closest town, it went to 6.2V and quit.

Should have seen it coming. Towed back to Chevy dealer that was open Saturday morning, alternator shot. New alternator installed.
Came back home, no problems. Problems with no start, dead battery, started about 6 weeks after that.
Could a cell or more have finally gave up, and I did damage to the battery when I let it run down to 6.2V ?

Will do the checks and go for new battery, as this Delco has a 5 year warranty, I may get away with a pro-rated exchange, if that is it.
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Old 04-09-2005, 08:54 PM
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It is probably hidden in a black wire loom if it hasn't been touched before. Take off your left gill panel and take the battery out. Then look for a 12g red wire going from the junction block towards the alternator. It should run somewhere near the battery tray itself.

Do you have a multimeter?
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Old 04-09-2005, 09:12 PM
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Originally Posted by scorp508
It is probably hidden in a black wire loom if it hasn't been touched before. Take off your left gill panel and take the battery out. Then look for a 12g red wire going from the junction block towards the alternator. It should run somewhere near the battery tray itself.

Do you have a multimeter?
Check the fuse block behind the battery. Same thing happened on my car.
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Old 04-09-2005, 10:13 PM
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Hmmmmmmmmmmmmm...........

Now this is really some funny arschficken Scheisse here. I took the alternator to Advance Auto Parts and and also Autozone and both of them tested it. It was 10 volts on both stores! WTF!!! Normal range is 14-16 volts. Its a Delco remanufactured P.O.S. even if the saleperson who traded me the Vette said he changed out the old alternator for a brand new one. Now when I tested the resistance between fusible links, and also from the alternator to the ground, there was actually a connection. Wasted about 2 hours just trying to fiddle and clean the battery teminals and all the wires. And now my battery is 6.8 volts. I'd like to charge it ASAP. Is my battery permanently damaged?
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Old 04-10-2005, 05:34 PM
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(huh huh huh.... he said "Scheisse"...)

well i'm glad you found the problem. as for your battery, you might as well haul it down to Advance/Autozone to get it tested. if the alternator crapped out it shouldn't mess up the battery, but it won't hurt to check. if it's fine just remember to use a dedicated charger to get it back up to 12V. a bad battery on the other hand can mess with the alternator.

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Old 04-10-2005, 05:43 PM
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As was said....

If you have an alternator fail the battery gets stressed to lower voltages. When you put a new alternator on without charging the battery back up to par with a dedicated charger the new alternator get stressed and can weaken.
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Old 04-10-2005, 09:43 PM
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I just tested out my battery and right now, its 6 volts. I'll be getting a charger tomorrow from Autozone. How long will the battery last if it is under 7 volts? If it has been under 7 volts already for the past 3-4 days, it is already toast?? FYI, both the battery and alternator were all bought brand new when I got the car on Dec 23, 2004.
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Old 04-10-2005, 10:15 PM
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If the battery was in good shape before it was discharged it should be fine. I would put it on a nice slow charge ie don't let it get above 2 amps and slowly bring it up to full charge. I bet it will be fine.


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Old 04-11-2005, 12:44 AM
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Your battery is probably ok and if you bought a 10 amp charger, it will automatically reduce the charging current as the battery becomes charged. Be aware that a battery as dead as yours will draw a lot of current at first when you put your new charger on it. Your alternator is clearly defective at 10 volts output. If it is under warranty, exercise your warranty and get a good alternator in there.
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Old 04-11-2005, 03:52 PM
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Did not mean to hijack this thread, but same subject. JFB, I took the
4+ year old Delco 750 CCA back to Bennett Auto Supply here in south FL, they read the code, said it is over 4 years old.
They did an exchange for a 950 CCA Delco for a total of $42.85. The battery I was trying to charge was DOA.

Cost out, believe this ? They gave me $79.79 for the old battery.
Charged $1.50 core charge. Battery Adj: $36.12 Battery Tax: $1.50
Sales tax: $3.73.

Surprised me that Delco would eat that much.
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Old 03-14-2019, 03:24 PM
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Default Alternator in c4 1984


I read all pots We have the same problem nothing resolved i
Hsve 4th alternator and nothing. Every mechanic ssys is alternator and spend money

Last edited by Sandra Funes; 03-14-2019 at 03:27 PM.
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Old 03-15-2019, 11:09 AM
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Originally Posted by Sandra Funes View Post

I read all pots We have the same problem nothing resolved i
Hsve 4th alternator and nothing. Every mechanic ssys is alternator and spend money
Sandra;
1st welcome to the forum. Why don't you start your own thread explaining all that has been done and your symptoms and I'm sure someone will have an answer for you?
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Old 03-15-2019, 04:11 PM
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Originally Posted by kopbet89c4 View Post
I just tested out my battery and right now, its 6 volts. I'll be getting a charger tomorrow from Autozone. How long will the battery last if it is under 7 volts? If it has been under 7 volts already for the past 3-4 days, it is already toast?? FYI, both the battery and alternator were all bought brand new when I got the car on Dec 23, 2004.
Some things of note:

1) Every time a battery goes that low, it takes a hit. If it's left low, it will sulfate. Do yourself a favor and buy a battery tender that desulfates such as the Batteryminder or Cetek. It will not change the fact tha the battery took a permanent hit. That being said, I have had batteries that were accidentally discharged a couple of times and after properly charging them, they are still running.
2) If the battery is that low, and you jump it and let the alternator charge it, it's going charge very aggressively - that makes heat in the battery which is bad for the plates. Best to properly charge a discharged battery than let the alternator do it.
3) If it's a healthy alternator, it can full field and be fine - if it's older or on the border, sometimes it's a bit too hard on them.

Last edited by Ed Ramberger; 03-15-2019 at 09:30 PM.
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