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car dead twice...help

04-23-2010, 10:25 AM
tried to post earlier but no dice

yesterday morning when i was walking into work my car alarm went off for no reason in the parking lot. then when i got out 4 hours later it was dead. i jumped it last night and drove home(which isnt far) and it was dead again this morning. no lights were on and i made sure all doors, hood and trunk were closed. my car was locked but the alarm didnt go off last night. my battery is fairly new, but a cheapy one. terminals r tip top and alternator was changed like 2 years ago but has been strong and charges great. could my alarm be messing with the battery somehow? how do i fix it and keep the alarm? thanks
SAMSUNG-SGH-A877/A877UCID3 SHP/VPP/R5 NetFront/3.5 SMM-MMS/1.2.0 profile/MIDP-2.1 configuration/CLDC-1.1

04-23-2010, 11:49 AM
It could be anything at this point.
Use an ammeter to check your quiescent current draw.
It should be less than 500 mA (0.500 A).
If the car is drawing more than 500 mA, you need to isolate the circuit that is causing this.
You can start pulling fuses until the current drops.
If you suspect the security system, you can temporarily disconnect the brain to see if it brings it down.
If you have never used an ammeter, follow these instructions:
Make sure the ignition and all accessories are off.
Disconnect the positive battery cable.
Set your multimeter to the ammeter setting.
Connect the ammeter's positive lead to the positive battery terminal.
Connect the ammeter's negative lead to the positive battery cable.
If the security system is still connected, use your remote turn it off, if it goes off.
Leave the ammeter connected and wait a minute or two to allow the electrical system to stabilize.
Now read the current displayed.
If it is less than 500 mA, this is not your problem and will have to look elsewhere for your troubles.
Report back with the results.

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