98 Chevy Lumina and Discharging Battery Problem

I have an excellent mechanic but this is one problem that he’s having trouble fixing. My car has been in the shop four times since September and I’m afraid that if I call for a tow again, he’ll ignore my call when it comes up on the caller ID.

My battery was replaced one year ago and then again replaced under warranty this year. My battery keeps being discharged for no reason at all…it usually happens after it sits for a day without being ran. My usual driving habit is to set the parking brake every time I shut down the car, to keep the day-running lights from coming on…and I rarely drive out of town. I know that these Luminas are known for this problem. My dad suggested running an extra ground wire from the engine block to the firewall and so far I haven’t found one in our local car parts stores. I did find a battery ground strap but I’m not sure that it’s long enough to reach the firewall.

Running another ground wire between the battery and the dash isn’t going to fix this problem. There is a parasitic drain on the battery while the car is parked and you need to find out what circuit is having the trouble. I assume this trouble is intermittent since it has been going on for some time now. This would be hard to pin down if that is the case. You may need to take the car to a shop that is better set up to handle this kind of trouble. A shop that specializes in electrical trouble should be able to help you. There are devices available that monitor the battery while the car is parked and will set an alarm when the current drain changes. The tech can then check the fuses and see which one leads him to the trouble area.

Battery drain questions have been asked, and answered, before. To see some of those answers, go to the red banner at the top of this page and click on Search. In Keyword, put: battery drain. Submit. Electric motors use the most power, and would, therefore, cause the most drain on the battery after shutdown. Electric motors are: the engine cooling fan(s), and the heater/ AC blower, power seats, power antennae, etc. A 1/2 hour engine shutdown, none should come on; but, sometimes, the engine cooling fan does (faulty relay). A while after shutdown, go to the car and listen for fans, motors, clicking relays, and look for lights. If you see, or hear, any, tell your mechanic.

Both previous suggestions are excellent, but one more thing that you can check is the trunk and hood light if so equipped. If the car does have them remove the bulbs and see if the problem continues.