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Alternator is draining battery while key off and getting hot

  • Thread starter Thread starter chipstadley
  • Start date Start date Oct 4, 2011

chipstadley

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Sep 8, 2011
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Oct 4, 2011
#1
  • Oct 4, 2011
  • #1
Thought it was a bad alternator so replaced it, still getting super hot when off and alt is plugged in, checked all the wiring to starter relay and replaced relay, fuseable link on it is getting hot to the touch but not burnt out, alt is drawing very small amounts of voltage from the battery just enough to drain it if I leave the battery hooked up for a couple of hours, I a m totally stumped and dont know what else to look for, didn't have the problem until I relocated the battery to the trunk, I have since moved it back to its stock position. I know it is the alternator draining the system because once it is unplugged it stops draining the battery, I messed with it for about three days now havent done a thing different and since the voltage drops alot slower now. HELP me if you know what it could be please please please.
 

Mintsick

10 Year Member
Jan 6, 2007
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West Lafayette, IN
Oct 4, 2011
#2
  • Oct 4, 2011
  • #2
I didn't have your exact symptoms but I had a battery draining issue, I replaced battery and alternator and it still did it...It ended up being a couple of the fusible links that sit below the battery tray, replaced them and all was good. There is a wiring diagram around here (Jrichker posts it to help people a lot) that can show you where they are.
 

jrichker

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Oct 4, 2011
#3
  • Oct 4, 2011
  • #3
Pull the alternator and take it to one of the auto parts chain stores - AutoZone, Advanced Auto Parts, etc. They will test the alternator for free, out of the car or in the car. The odds are that one of the 6 diodes in the alternator has an internal short.

Once you get the alternator working properly, I will post the directions for the correct way to do a rear mounted battery that will pass Tech at any race track.
 

90lxcoupe

20+ Year Stangneter
Oct 7, 2003
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Oct 5, 2011
#4
  • Oct 5, 2011
  • #4
If you take it to autozone, take it to 2 different stores. Autozone told me the alt was bad, kid seemed like he didnt know how to use the machine so i took it to advanced and they told me the alt was fine
 
I

interceptor7

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Aug 11, 2006
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Oct 6, 2011
#5
  • Oct 6, 2011
  • #5
For what it's worth, I had the same issue recently, and it was the alternator. It threw me off because it would still charge fine with the engine running, but would drain it when sitting overnight. Internal short.
 
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