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Battery drain w/n 24 hours ...cadillac

I HAVE A SEVERE BATTERY DRAIN IN A 2000 DEVILLE I CHECKED EVERYTHING IT RANDOMLY GOES DEAD OVERNITE…I TRIED AUTO LAB …DEALER… LIGHT BULBS ETC…STILL NOTHING…PLEASE HELP

The best way to find the trouble is to place a ammeter in series with the negative battery lead and monitor the current flow. Then pull fuses one at time to see which path the drthain is on. Normal draw on a battery should be less than 80 milliamps. Make sure you let systems go into the sleep mode when reconnecting circuits.

The usual suspects are the automatic door locks (one may be sticking) the alarm system, the trunk pull-down, (it does not click off and keeps pulling down).

An alternator can drain the battery too. It’s going to be fun.

ITS NOT LOCKS OR TRUNK OR LIGHTS I DONT KNOW HOW TO CHECK ALARM…THNX

I DONT KNOW HOW TO DO THIS BUT I WILL LEARN FROM AUTO STORE…THNX

How old is the battery? That may be the problem.

That’s easy to confirm or eliminate. Just disconnect the battery over night, and then re-attach it in the morning and see if the car cranks. If it does, then the drain is in the car (most likely), if it doesn’t, then the drain is internal to the battery. In that case, the fix is easy. Replace the battery.

So this does not happen every night, only some nights, right? Intermittent problems like this are hard to track down. Something must be turning on sometimes and not others. Does this car have some sort of automatic headlights? Can you turn them off, completely off? Try that. How about automatic windshield wipers. I would think you could tell if they have been running. This car has a lot of electrical accessories so tracking it down is time-consuming. You could pull some main fuses every night and see if the problem goes away. After that, some of the subs, or pull them in groups, the same ones for several nights and see if the problem goes away. If it does, then try to pull the individual fuses to get the specific circuit. An auto electrical shop might know of issues with this particular model. This will be a real pain if it is intermittent.