Question: I've got an 88 4 cylinder Fiero and its got a new battery. It starts fine on a jump and all day after that but I let it sit for a few days and the battery is dead. Any ideas on what's causing this?
Answer: Several things to check:
1. Have a load test done on the new battery to make sure it is not bad.
2. Lift hood and watch/listen to headlight motors to make sure they are not attempting to stay running. Crumbled drive pins can allow this to happen.
3. Open fuel door, remove cap and listen to make sure fuel pump is not running. A bad oil pressure sending unit can allow this to happen.
4. With voltmeter between battery negative post and ground, observe to see if any currant is moving. About .01-.03v should be all that is.
5. If more, remove alt energizer wire from alt stud. Alternators can discharge a battery when static and still charge them when running.
6. If drain is not found yet, leave voltmeter attached and remove fuses one at a time until shorted circuit is isolated.
7. If BAT fuse is blown, a shorted horn, cigarette lighter, or radio memory circuit will cause overhead lights to glow softly. These circuits will find a ground through them. Disconnect one at a time until lights stop glowing.
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