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My 81 has something draining the battery when it sits. Using a test light, pulled all the fuses and the alternator wire but something still pulling on the battery. Any suggestions on where to look next?
Thanks for the help. (:
Over the years there were some pretty good stories about "Parasitic" draw that were hidden.
One was a light in the spare tire carrier. Not sure what yrs had that.
Another was a under hood lamp.
Then another was the wiper motor or wiper rely? Again, don't know what yr.
But all of those situations would (OR SHOULD) show up on a ohm meter at the fuse panel.
Last edited by HeadsU.P.; Nov 7, 2020 at 08:06 AM.
Most radios and such can pull 200mA....that will kill a battery pretty quickly.
Measure the drain at the battery.
One quick work around is to install a Green Switch battery cut off on the neg of the battery.....when you get home you disconnect.
I would think that this drain is in the mA range otherwise you'd be getting warm wires somewhere.
And YES, disconnect the underhood light completely....they have a mercury switch and you really never know when G forces can turn it on. Creepy feeling to come into a dark garage and see light seeping out of the hood!
Do you have a multimeter with a current measuring circuit? How much current is being drawn?
With the alternator disconnected, and all fuses pulled, all that is left is a short within the starter, or possibly the starter extension harness.
Do you have any other wires tapped to the battery, starter, or elsewhere, possibly added by a previous owner?
Here's what the starter extension harness looked like in my 80, before I replaced it. If yours has also melted away the fusable link insulation, but hasn't yet failed, you may have a short there. In my case, it was a lot easier to see with the exhaust manifolds removed.
81 Battery Drain
