1986 Ford Mustang Battery Drains overnight

Tiny
MUSTANGNORM1
  • MEMBER
  • 1986 FORD MUSTANG
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 18,000 MILES
Just got my car tuned up, I had to boost it at the shop to get it home, battery was dead. If I don`t disconnect the battery at night it will be dead by morning. Had this problem before and they changed the ECM power relay, but this time that didn`t cure it. Even with the relay disconnected and everything turned of there is spark when I touch the cable end to the battery. I also tried this with the fuel pump relay disconnected and still have spark, do you have any idea where my trouble would be?

Thanks. Norm
Monday, December 17th, 2007 AT 3:24 PM

1 Reply

Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Hi there,

You will have to do a current draw test. Remove the Bat Pos(+) terminal and hook up an Amp meter between battery and cable, this swill show current draw. With every thing turned off and doors closed. Start pulling fuses one at a time, and watch to see if current draw drops. If no current drop with fuses undo alt feed (you may have a leaking diode) this should pinpoint your problem.

Mark (mhpautos)
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Monday, December 17th, 2007 AT 3:36 PM

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