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Battery HELP!!!!!


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A couple of things come to mind. The most obvious is, of course, is the alternator working? Any charging system messages ot codes?

If you are certain that your charging system is OK, then it very well could be a defective relay, or a shorted circuit. Does all the power equipment in the car work?

My dad once had a Lincoln of the same vintage as your Cadillac which had the same problem. He would jump start it and drive it, but once he parked it for the night it would not start. It turned out to be a defective fuel pump relay dumping the battery charge to ground.

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Hey val1212,

Like cadillacjeff says, it sounds like a parasitic battery drain. It is normal that there is some sort of drain, for the clock, memory in the radio, voltage regulator ecm memory ect; but it should be minimal...the fsm for my 1988 deville 4.5l says 50 milliamps is normal. It is not enough to discharge your battery in one day.

If you have a digital multimeter you can verify the current drain and determine if it is within range. My fsm says to set your mutimeter at 2000 milliamp range and connect the it in series (disconnect neg(-) batt terminal, connect neg(-) probe from mutimeter to neg(-) batt terminal and pos(+) probe to the end of the negative battery cable). If you have electronic level control (ELC), you must wait 6 minutes because it continues to draw 400 milliamps after the ignition is turned off. Make sure it securely connected (with alligator clips for example) because the elc will reset for another 6 minutes if the cicuot is broken. Also very important, when making current drain tests, make sure you disconnect the fuse to the interior lighting and disconnect the hood light...it will show current drain which could cause a faulty diagnosis if your door or hood is opened.

If you have more than 50 milliamps (maybe more with your eldo but it should be around there) you probably have a parasitic current drain.

To locate it, with your multimeter still connected, start disconnecting fuses till the exessive drain disappears. If you take out the fuel pump fuse (for example) and the exessive drain is gone the problem is in that circuit. Make sure the you took out the interior lighting fuse and disconnected the hood lamp. The multimeter might blow a fuse if it cannot handle the current drawn from the interior lights turning on when the door is opened ect...To check the hood light the hood must be closed. Yoy can just disconnect everything and look from under the car if it stays on when the hood is closed or by depessing the the switch the same with the trunk light.

If no drain can be found, the problem is elsewhere...faulty battery or charging system.

If this does not help, I am sorry for the long post...please correct me if anybody sees anything wrong with this.


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