'03 LS8 Battery Draw

[Gus_Mahn]

We parked my wife's '03 LS8 last Friday after work. This Sunday morning my wife went to drive the car, and it would not crank. This is second time this has happened. The battery is mostly dead, but takes a charge fine and tests good. Does any one have any experience with a draw on the LS's battery? Any tips for figuring out where the issue lies?

Thank You.

 

[Andrizzle]

Any aftermarket or altering of the audio system in the car?

 

[Gus_Mahn]

Any aftermarket or altering of the audio system in the car?

Nope! it's dead stock. It doesn't appear the trunk light is staying on, and I don't believe it has a underhood or glovebox light.

 

[gcwimmer]

How old is your battery, I know you said it test OK.

 

[joegr]

Your LS does have a glove box light. It, indeed, does not have a hood light.
Your LS has a battery saver circuit, so if it is stock, there is no way any of the lights can stay on and run the battery down.
After the car goes to sleep (about 30 minutes after the last switch/sensor is disturbed), the drain should be less than 50 mA.

What is the age of your battery? It could have a high self discharge and still test as good. How are you testing it? Are you using a true load tester?

If the battery is at or beyond the five year mark, then it needs to be replaced, and it needs to be replaced with the stock battery, or you will have to rig a vent.

 

[Gus_Mahn]

Battery is two years old. I have a load tester, and I've done cranking test. I blew up my amp meter trying to figure out a draw on my Safari van (it was internal to radio), and Harbor Freight was out of replacements today. I'll try back later in the week. Thanks of the information.