zeep99xj

My 99 xj is draining batteries like crazy. I first noticed something was up when i was stopped at a red light and my radio started tripping out so i turned the jeep off and when i tried to restart it i got nothing, not even electricity to my radio or lights or anything. It eventually started up after being stuck in the middle of the street. Then the other night i went out to leave and the jeep wouldnt start at all. The battery was completely dead. I replaced the battery and battery cables (something i had been meaning to do) and it started up and drove fine. The next morning it was completely dead again. I got another new battery and put it in drove it to the shop and immediately disconnected the battery cables. Im waiting to hear from the shop but in the meantime what do you guys think it could be? I do have an amplifier hooked up that might not be shutting off with the car, ill have to check that out when i get it back. But what else could cause a battery to just drain over night like that? Electrical short? Please help get my baby back on the road!!

tjwalker

The first thing you have to do is verify that your CHARGING system is working properly.

What does the voltage gauge on the dash read with the engine running? Should be in the 13-14 range. You can also verify this with a meter at the battery.

Is the serpentine belt that runs the alternator tight?

If charging system checks out and you have already replaced the battery, it is time to get out the meter and search for the root cause of the drain.

zeep99xj

Yeah the alternator and everything are fine. Thats the first thing i checked. The battery is being drained while the car is completely off. Would some kind of short cause that?

zeep99xj

Just got it back from the shop, the mechanic said he checked everything with a volt meter and everything checked out fine. And he left the battery connected over night and it didnt drain, this was all with my amp disconnected though! So im guessing thats my problem. Could a 500 watt amp really drain a battery over night? The battery that it drained was rated at 750 cca. The amp does turn off when i kill the engine so i dont know what would be causing it to kill the battery. Im thinking about just putting in a kill switch on my amp's power cable. Shouldnt that solve the problem?

tjwalker

Yes, if the amp is the culprit.

Too bad you didn't have the amp connected for him to check for drain caused by that.

4jeepers

Install a power on/off switch to the amp. However if your alternator output is not high enough to drive the amp and charge the battery when using the amp, you will need to replace the alternator with a high output alternator.

zeep99xj

I have had the amp installed since ive had the jeep, about 2 years, and this is the first problem so im hoping my alternator is fine