2005 Outback about 100K.  standard engine auto.  When just sitting there I get around a half amp draw from the battery.  pulled all fuses inside and engine compartment with an ammeter attached to monitor draw.  NOthing.  except back up lights showed slightly less draw.  Any thoughts on usual problems with this car.  best place to look for possible slight ground?

Pull the fuses under the dash aswell to narrow down the location of the draw.

Another possible path is through the main alternator output wire. Partially failed rectifiers can do things like that. Simple to check, just un bolt it. But it is live if the battery is connected, so pull the GND (-) side first.

Make sure you've let the thing sit long enough for the computers to shut down. 30 mins should be long enough. Your back up lights shouldn't be drawing anything key off, but if that doesn't drop you down below 0.050A, then it's not your main issue. I'd agree with the alternator, try pulling the connector and the charge wire.

pulling the battery cable fully discharges all systems.

 

Reconnecting via a multimeter causes a large ramp up draw for computers and electronics right?

 

So maybe you're just seeing that initiliazation draw rather than nominal draw?

Edited January 18, 20179 yr by grossgary

Are there any custom installs or electrical work done? Phone charges, 12 volt recepticles, stereo, remote start, car alarm, DVD, lighting, custom HIDs, etc.

 

Or any components not working correctly or intermittently? Any recent repairs before this stated?

 

Those are common areas with issues.

if there's unswitched voltage going to the hatch, maybe chafed/shorting wires in the boot from body to hatch?