1G Alt No Charge, No Battery Light on Dash; Please Help!

[greekgodchaos]

In short:

• Alternator tested GOOD, but doesn't charge
• Battery is fully charged, but isn't getting charged by the alternator
• The Alternator 80 amp fuse is fine
• The Alternator "Relay" is fine
• The Battery light on the dash is NOT illuminating when they key is in the ON position, and the bulb is FINE
• All bare-metal connections were sanded for ideal connections
• The 10 amp Instrument Cluster fuse is intact

As I was driving home the other day, my car began to act up; bucking, misfiring under load, and my voltage was around 10v running, so I pull over, kill it (derp), try to start it up and nothing (DUH). Thank God for bump-starts I was able to putt home.

I got the alternator tested and it was good, I had to parallel charge my battery back up to normal (Optima Red Top), and now that's fine.

The Battery light on my dash is NOT coming on when you have the key in the ON position.

The 80 amp Fuse is fine, the cables from the Alt to the Battery are fine, and everything is as it should be.

There is one thing I was a bit confused on; in the OEM Electrical manual, there is a mention of a 10 amp fuse in the line from the IGN to the Alt, which I can't seem to locate (unless it is part of the instrument cluster 10 amp fuse in the footwell, which is intact) and the bypass relay tested fine as well. I even removed it and applied jumper leads for quick testing to make sure the connection was okay and thought it would make my battery light come on: nothing.

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HELP!!

 

[92AWDHX40]

how old is the battery I had a batter chafed up it still wouldn't charges problem solved with a new battery

 

[donniekak]

Who tested the alternator? I've had autozone say a know faulty alternator was tested good.

 

[19Eclipse90]

Fuse 11 is in the Junction Block (J/B) which is in the cabin's driver side foot well fuse box. Yes, it is the 10A fuse labeled "GAUGE".

How did you test the alternator?

 

[GST with PSI]

Sounds a lot like the issues in this thread: http://www.dsmtuners.com/threads/alternator-trouble-still.496787/#post-153541802

How did you verify the battery light bulb was good?

 

[greekgodchaos]

The battery is about 3 years old...right out of warranty wouldn't ya know.

The alternator was tested at my local Cost Less Auto Parts on the bench.

Checked the 10 amp "Gauge" fuse, its intact.

I swapped the lights with a known good bulb (the one right next to it) and it still didn't come on, but the door ajar light still came on with the bulb from the Battery slot.

 

[donniekak]

Unplug the 2 wire connector and just leave the battery connection to the alternator. Start the car and rev it to around 4000 rpms. Check voltage and see if if the alternator is charging, if it isn't, it's bad. This doesn't mean there isn't a possible issue with the battery light circuit, just a fail safe way to test the alternator.

 

[greekgodchaos]

Taking your test shows that the alternator is indeed NOT charging at 4000 rpm. Why the hell do these show good on the bench but are bloody useless IN the car? That's so annoying.

 

[donniekak]

Taking your test shows that the alternator is indeed NOT charging at 4000 rpm. Why the hell do these show good on the bench but are bloody useless IN the car? That's so annoying.

I really don't know exactly how they test good when bad, but after having a dsm forever, I know they do.

They don't even test my alternators at autozone anymore, they just cough up a free lifetime replacement every 6 months to a year. A couple years back I had one test good on their machine. I put it in my car, drive it over and it tested bad. No clue.

I actually know people that never plug in the 2-wire harnes, and just run them full blast. I think this shortens the life span even more though.

 

[greekgodchaos]

Went to my local Pick n' Pull, grabbed an alt, and lo and behold! Sitting pretty at a 14.9v.

 

[greekgodchaos]

This also seems helpful on voltages http://www.dsmtuners.com/threads/alternator-help.285476/#post-151425654

 

[GST with PSI]

Taking your test shows that the alternator is indeed NOT charging at 4000 rpm. Why the hell do these show good on the bench but are bloody useless IN the car? That's so annoying.

I think many times it's because the alternator isn't exposed to high heat on a test bench like it is when installed on the car. Half of the time, the heat from being in close proximity to the exhaust parts is what kills the rectifier/regulator. That being said, I've had new alternators DOA right out of the box.

I purchased a new alternator from a local parts chain one time. Got it home and on the car, and it wouldn't charge. I took it back to the parts place and it tested bad on their machine. They gave me a new one, and I made them test it before I left the store with it. It tested bad right out of the box. At that point, I just asked for my money back.

I went to the junkyard a few days later and found a crusty a$$ OEM unit on a 1G Talon. I pulled it and figured I'd take the chance for $40 bucks. I cleaned it up, and threw it on the car. It was still working 5 years later up until I sold the car. I bet it's still working till this day.

 

[greekgodchaos]

The moral of the story: junkyard alternators are superior to rebuilt from the store