Why does our battery keep going dead?


Asked by Jun 01, 2015 at 01:20 PM about the 1999 Cadillac Eldorado Base Coupe

Question type: Maintenance & Repair

we keep putting batteries in the car and within a week it is dead.  We just put $500. into
and it was good for 3 months and we out to start it the other day and it was dead. There
has to be something draining the battery.  They put a new diode in the alternator, new
radiator, and just general maintenance on it.  I am hoping you can help us.

5 Answers


Best thing I could say is the alternator in its entirety needs to be replaced. Or you can disconnect the battery when not using your vehicle to avoid the drain. Sorry probly not the answer your looking for but those are my suggestions


there is a electrical draw when the key is off,a time control module,there is a way to check for a battery draw,you'll need a multi tester and locate your fuse panel,start removing 1 fuse at a time and watch your meter,I believe it's no greater than 10amps.Simple solution is install a battery disconnect switch.on the neg.side of cable.have fun?

Ralph Best

If you have replaced the A/C Compressor or any other major components under the hood you will have to reflash your cpu or your blower motor will run on high speed intermittently while the car is shutoff and you are in bed. I KNOW THAT YOU MUST THINK INIM CRAZY BUT CADILLAC IS THE ONE THAT FIXED MY 99 ETC. I replaced the a/c compressor and recharged. Thought everything was good. But 2 days later my battery was dead. Call Cadillac they will comfirm.

1 out of 1 people think this is helpful.

To test for a voltage drain you need a voltage tester. You can go on utube to see how to check for voltage drain. There is another simple and easy way you can check for voltage drain. First make sure battery is fully charged connect negative terminal to negative post on battery then take the positive terminal and slightly drag it across the positive post on battery if you get a little spark and ark your battery is being drained. Remove each fuse one by one and also remove connections to alt if you find the drain there will be no more spark and ark. You may went to do this with two people to keep from running back and fourth from the hood to the inside of the vehicle


Hello, Does you Caddy have the feature that allows you to use in the inside electrical until you open the door after you shut off engine... IE, like you pull up, cut car off, and have radio, windows, etc, until you open the door...?? If so, the module that works this can cause same problem WHEN it is defective OR IF the ignition switch mechanism is slightly worn. If you see your LED lights on the radio, or the clock when ignition is off, door open...EVER, then look into this area. There are tons of things on Caddy's and Lincolns that can cause this, but for your model, this is a biggie known issue. The others, leaking air ride, compressor comes on too often when you are away; diode trio bad in alternator leaving line feed back to fuse block, and others. It takes a real specialty guy to work on Caddy's and Lincolns...I know...My back knows...and I am tired from THIS! :) Hope this Helps, AskTrannyMan

1 out of 1 people think this is helpful.

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