Parasitic draw -
  • 1 Post By ronjenx
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post #1 of 4 Old 01-28-2020, 06:28 AM Thread Starter
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Parasitic draw

07 jeep wrangler 3.8l, has some offroad lights, headunit with sub, amp, and speakers.

Past couple months my jeep has been having trouble starting. I got the battery and alternator checked and the both were in good working order. The other day it didnt start, jumped it, let it run for 10 min, shut it off, sat for 10 min, didnt start back up. Jumped it again, drove it for a few miles, shut it off for 30 min and it fired back up. Yesterday morning she was dead dead, couldn't even unlock the doors, no lights, no crank. Jumped it and she was fine.
Last night I hooked my multimeter in series with the battery to see if there was a parasitic draw, I was getting .15a. To me that sounds normal. I started unplugging fuses but none changed anything, I havnt finished this because I ran out of time.
Anyway this morning she didnt start again, so whatever is drawing power is getting bad, to the point where 3 mornings in a row I've needed to jump it.
So once If I finish pulling fuses and cant find the problem, what should I do next? How can I test to see if my radio/ sub/ amp are drawing? Or could the auto shops battery/alternator give a false reading?

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post #2 of 4 Old 01-29-2020, 09:02 AM
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2014 JK Wrangler 
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How old is the battery?

2014 JKU Copperhead Pearl
Too many mods to list. Too awesome to sell.
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post #3 of 4 Old 01-29-2020, 09:20 AM
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Try disconnecting the battery at night. If the Jeep starts easily the next morning you know it might just be the battery is going bad.
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post #4 of 4 Old 01-29-2020, 09:53 AM
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2008 JK Wrangler 
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Normal stock JK ignition off draw is 0.035 amps, or less.

When your meter is connected to check for draw, wait three minutes to let the computers go to sleep. If you lose continuity with the meter, the three minute wait starts over when you reconnect.
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