In the past week I developed a serious 6 hour battery drain. I used my meter to isolate it to fuse 11 which controls the horn relay, interior lamps, lighter, hatch motor, power antenna.
The meter does not show a constant drain. It jumps to 4.6 amps, drops to zero, stays there for 3 seconds, jumps back up to 4.6 amps and drops to zero again. Very odd.
I have the meter set on 10A. The hatch motor, horn and interior lamps work. The power antenna has been kaput for 6 months, but that only runs when the ignition is on.
I replaced the ECM 5 months ago. Other than that, nothing new. Any ideas? Thanks. Mark

 

Did you look in the cigar lighter hole to make sure there isn't something inside there?

 

Sounds like something with a self-resetting circuit breaker in it.

Probably not the interior lights. Might be some aftermarket thing like an alarm or remote start.

Disconnect each of those things, that you can... unplug the power antenna, disconnect the radio constant-hot feed, unplug the hatch motor, etc. When you disconnect something and it goes away. … bingo.

 

Check the trunk deck lid pull down, I had one of the contact switches go bad years ago and it took me for ever to figure out that the pull down motor wasn't shutting off, because it wouldn't occur after the battery died and I charged it back up, until you opened and closed the trunk, at which point it would kill the battery again. I even took it to a mechanic who never opened the trunk so he never saw the drain.

I would take the back pannel off and run the hatch motor about 1/2 down and unplug it and the switches and see if the drain occurs.

 

Since amps keep changing from 4.6 to 0, then back to 4.6 every 5 seconds or so I suspect that may be the culprit. alarm was disconnected years ago.
If it was the lighter or interior lamps, the amp draw would be constant. Thanks. I will try the hatch motor. That draws a lot of ampos by the way vs the lighter or interior light.

 

Yes, clean and the lighter works as it should