Background:

97 GS, MTX.

Thought I had a bad alternator.

Symptoms:

Battery light came on.
Could not start the car unless jumpstarted.
No power WHATSOEVER, even with the key in the ACC position.

Remedied:

Cleaned off connections to the battery terminals.
Bought new battery. ( Other one tested as bad )

Results:

Got power
Can start the car without jumpstarting.
*NO battery light*

My questions:

Will the battery light come on BEFORE the battery is drained due to a faulty alternator?

I tested at the battery for voltage with the car idling and got 12V, and also at idle with the lights on and got 12V. Is this the proper way to see if the alternator is functioning properly and not draining the battery? Is this the voltage I should be seeing in this situation?

Thanks for your help.

While I don't know the details of testing the alternator for proper output, I can tell you that there is a specific proceedure listed in the Chiltons for doing so. I'm sure you have one of those lying around, boss. I also believe the battery light will come on whever the ECU detects a drop in voltage. Before my last battery conked out on me, the batt light would come on intermittantly at red lights and then go out at speed. Take this how you wish. Just my experiences. :shrug

Cool thanks DR.

Anyone else please share your experiences and thoughts!

Well the 12 volts at the batt is good, but that's not the best way to test the alt.. That tests the battery. Now I have never tested it that way before, but I would think that if your alt was not charging the batt. you would see a voltage drop there. Just go to auto zone and have them test it for free..lol. Don't you have the apexi TT? If so take a look at the voltage readout and see if you have 13ish volts at idle...

Thanks Kirby. I have a Blitz turbo timer, however this is on my bone stock silver 97, not my green car.

My thoughts are that since the battery is not seeing a voltage drop, that the alternator should be maintaining its voltage.

I have heard that it should be somewhere near and/or above 13.5 volts to be working properly.

Anything electrical OWNZ me!!

are the connections crimped?

Originally posted by SILVERNT
are the connections crimped?

Saw that coming.

If the battery is at 12V with the engine off, it will take more than 12 volts to actually charge it. You need a voltage difference for the power to flow. From what I've seen, you see 13-14V at the battery when the car is idling and 12V with the engine off. If the voltage at the battery doesn't go up when the engine is running, it sounds like the alternator is not operating or not hooked up right. I imagine that you'll kill this new battery if you don't fix the problem.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

Originally posted by Corbin
If the battery is at 12V with the engine off, it will take more than 12 volts to actually charge it. You need a voltage difference for the power to flow. From what I've seen, you see 13-14V at the battery when the car is idling and 12V with the engine off. If the voltage at the battery doesn't go up when the engine is running, it sounds like the alternator is not operating or not hooked up right. I imagine that you'll kill this new battery if you don't fix the problem. Corbin '95 ESI-T Now with more power and fewer leaks Gimme fuel...Gimme fire...Gimme that which I desire

But wouldnt the battery light come on if there was a problem with the charging system?

Thanks Corbin.

Originally posted by 95greenhrcgs

Originally posted by Corbin If the battery is at 12V with the engine off, it will take more than 12 volts to actually charge it. You need a voltage difference for the power to flow. From what I've seen, you see 13-14V at the battery when the car is idling and 12V with the engine off. If the voltage at the battery doesn't go up when the engine is running, it sounds like the alternator is not operating or not hooked up right. I imagine that you'll kill this new battery if you don't fix the problem. Corbin '95 ESI-T Now with more power and fewer leaks Gimme fuel...Gimme fire...Gimme that which I desire

But wouldnt the battery light come on if there was a problem with the charging system? Thanks Corbin.

The battery will more than likely hold a charge for as long as it can and then when you start draining it the voltage will drop from the battery and the CEL will come back on. You need to take the car and havn't checked at Advanced or Auto Zone..






Newbies learn the hard way!!!

I had those same symptoms. My bat was new tho and at a stop light the bat light came on and then went off when i got going. And i parked my car and came out later and had to get a jump. I took the bat to kragen and they tested it and it was good. I cleaned the terminals off on the bat and clean the bat cables good. Then i tightened them up nice and snug and no problems. An arbst tester or equivalent would be the proper tool to use to test the alt.

OK. I have a new alternator sitting around, so I guess I will install it on New Year's day.

Thanks for your help fellas!