The Story:
Car ran with a new battery for a couple days with rough idle. The next day I had to hold down gas pedal for it to run... wouldn't idle. Next day I had to hold down pedal just for it to start. The next day the whole car went dead. I recharged battery and it started all over. ECM threw Coolant Sensor and TPS Error Codes.

I took my alternator up to autozone and it tested out at 16 amps I guess it was. 16 something which was in the green area so they said it was okay. Tested it 3 times.

Now what? The battery is being discharged somewhere but I can't find where... The connections and wires all look okay. I disconnected the wires to running lights and exterior horn but it still does it. I can't figure it out. Are there any other parts that could be causing it, or is it just a short in the wires somewhere and how do I check this.

-Shaun

Possiby a bad door switch is causeing your courtesy lights to stay on.It may also be the pin switch under the hood or trunk if you have a light in the rear.Is your radio hooked up properly?Checky your car at night and look for any lights that may be on.

A courtesy light doesn't drain a battery in 2 hours flat.

-Shaun

If you do not have an amp meter you can use a test light to look for the drain. Disconect the battery cable and hook the light up in SERIES to the cable (meaning the test light is now serving as a battery cable). If the light is on you have a draw. Start disconecting things till the light goes out. It is that simple, the thing that is turning the light on is where the trouble is at. Have the key OFF when you are doing this and keep in mind that if you open the door to get at the fuses the dome lights will be on, creating a draw.

If there is a draw and you are not finding a fuse that makes the light away disconect the read wire to the alternator. It is not fused and the Autozone guys are not electrical people, they could have missed this.

Aaron

Aaron

[This message has been edited by Electrathon (edited 01-26-2003).]

disconnect positive or negative cable? attach the test light to the battery terminal and battery cord?

-Shaun

Disconect either cable, whichever is easiest. The test light works in series to the cable, like you are lengthing the cable. Attach one end to the battery and the other end to the cable that you took off the battery.

quote Originally posted by neghcho: The Story: Car ran with a new battery for a couple days with rough idle. The next day I had to hold down gas pedal for it to run... wouldn't idle. Next day I had to hold down pedal just for it to start. The next day the whole car went dead. I recharged battery and it started all over. ECM threw Coolant Sensor and TPS Error Codes. I took my alternator up to autozone and it tested out at 16 amps I guess it was. 16 something which was in the green area so they said it was okay. Tested it 3 times. Now what? The battery is being discharged somewhere but I can't find where... The connections and wires all look okay. I disconnected the wires to running lights and exterior horn but it still does it. I can't figure it out. Are there any other parts that could be causing it, or is it just a short in the wires somewhere and how do I check this. -Shaun

16 amps? What? If your autozone has the same tester as my Autozone, they can NOT test amperage output of the alternator OFF OF THE CAR. Their units can only test voltage output which should be between 13.1 volts and 14.7 volts.

I would take the alternator to an actual automotive electrical repair center and have it professionally tested. If not that, get ahold of a volt meter and check voltage at the battery with the car running, it should be between 13.1 to 14.7 volts. If not, check voltage at the alternator battery terminal. If it is the same as at the battery and below 13 volts, either your alternator is bad or there is a problem with the alternator wiring circuit. If the voltage at the alternator is significatly higher than at the battery, then the alternator charge wire has an open in it somewhere -- most likely at the fusible link close to the other end of it. Also, does the battery light come on in the dash when you turn the key on with the engine not running? If not, check this bulb and make sure it works. If it does, your problem is either in the alternator or in the wiring from this bulb to the alternator. Good luck with your project.

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Fiero-related Conversions Performed:

1985 SE 3800 Series 1 SC 4T60-E
1987 Coupe 3800 Series II 4T60-E
1987 SE 3.4 TDC 5-speed

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I don't know whether it was amps or volts or what, but the needle was in the green area.

-Shaun

it was a 99% chance its 16 volts. have you unhooked the alternator and let it sit for 2 hours and seen if the battery still goes dead? if it still goes dead, then its not the alternator thats draining the battery.

matthew