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97 LaSabre Battery Drain...


ghink
06-21-2008, 09:28 AM
97 LaSabre Battery Drains almost dead in two weeks. New battery fully charged and tested.
When I put my test light between the negative post and negative cable the test light has a steady dim light and also pulses a tad brighter. Like as if the directional signal is on.
Any ideas?

HotZ28
06-21-2008, 07:37 PM
Do you know if the alternator is charging? You can test it with a DVOM at the battery. It should show 14.2 to 14.8-v soon after starting and trickle down to 12.8 to 13.2+v @ idle.

ghink
06-22-2008, 05:35 AM
The alternator is charging.

Do you know if the alternator is charging? You can test it with a DVOM at the battery. It should show 14.2 to 14.8-v soon after starting and trickle down to 12.8 to 13.2+v @ idle.

HotZ28
06-22-2008, 07:34 AM
Several items that come to mind that are notorious for causing battery drain are; ELC, power radio antenna (check to be sure it goes all the way down), glove box light, power door locks, blower control module, and of course the PCM/RAP/BCM. The following is considered to be normal drain items on these cars and the total should not be over 19.85 mA according to the FSM.

Adaptive Lamp monitor = 0.5 - 1.0 mA
HVAC Programmer = 0.5 - 0.75 mA
Gages Cluster = 4.0 - 6.0 mA
Oil level module = 0.1 mA
Radio = 7.0 - 8.5 mA
Amplifier = 1.8 - 3.5 mA

Total = 13.9 to 19.85 mA = 0.02 A max.
I put my test light between the negative post and negative cable the test light has a steady dim light and also pulses a tad brighter. If the light is lit, you are now ready to start pulling fuses/relays one at a time while watching for the light to go out. Also, you want to start with the main cockpit fuses first, but don't forget the other two fuse/relay panels.

After going through all the fuses one @ a time and the light remains lit, remove the battery cable to the alternator, then the starter. If the light is still on, disconnect the blower control module for the A/C fan. These are all “un-fused” feeds direct from the battery!

ghink
06-22-2008, 11:08 AM
Got lucky and disconnected my trunk CD changer and that was the culprit.
HotZ28, thanks BO for your help re this issue.

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