JSM Posted September 11, 2006 Share Posted September 11, 2006 2 weeks ago I jumped in and the battery was dead, 73 240z. Charged it and no go. Took it back to walmart and it was determined there was a bad cell. Jumped in yesterday and dead as a door nail again. Something has to be on or shorted. Is the voltage regulator suppossed to click when you connect or disconnect the battery? Is that an indication something is on? Where do I start to look? Mechanically, I pretty good, but electronics I'm a novice. Quote Link to comment Share on other sites More sharing options...
nismopick Posted September 11, 2006 Share Posted September 11, 2006 Did you leave your headlights on? Quote Link to comment Share on other sites More sharing options...
JSM Posted September 11, 2006 Author Share Posted September 11, 2006 Did you leave your headlights on? I'm not that electrically challenged! Quote Link to comment Share on other sites More sharing options...
JSM Posted September 11, 2006 Author Share Posted September 11, 2006 But that is a good point. Any door sensors that draw if they go bad or inside lamps that may stick on? Could a bad voltage regulator cause this? Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted September 14, 2006 Share Posted September 14, 2006 Troubleshoot. You are looking for the amperage (current) draw, not voltage, from the battery. Close the doors and ensure nothing is turned on (engine, radio, lights, etc.). Key in off position. Lift the negative lead off the battery and put a digital voltmeter between the negative post and negative lead. Polarity won't matter. Set the meter to read Ua (microamperes). If the meter indicates an error or fails to display then reset meter to Ma (milliamperes). You should see no current draw in a bone stock 73 unless you have a later radio with memory which will draw a very small current (6 or 7 Ua maybe) which will not drain a battery over a few months. You will see current draw if there is a drain on the battery. Disconnect the meter and insulate the negative lead from ground. Remove and insulate the leads off the alternator. Reconnect the meter to the negative cable. Does the current draw go away? If so, you have a problem in the charging system. If not, insulate the negative lead again. Reconnect the alternator and reconnect the negative cable to the meter. Open door and hold the interior light switch closed (in the door frame) or pull the interior light bulb. Lift one fuse at a time until the current draw goes away. That circuit will be the culprit to investigate. This is not difficult but is time consuming. A logical approach will aid you in resolving the problem. Quote Link to comment Share on other sites More sharing options...
JSM Posted September 17, 2006 Author Share Posted September 17, 2006 Thank you very much. This approach is exactly what I was looking for! Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted September 21, 2006 Share Posted September 21, 2006 buying a real battery like an interstate would help too. Been doing cars since 56 and been bit by the cheap battery and corroded battery terminals a few times. Don't ever buy a gel cell. They die when they get discharged. Quote Link to comment Share on other sites More sharing options...
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