Question about a weird electrical drain on a 2015 Civic

I had a car last week with a dead battery that kept coming back. The customer said it was fine for a day after a jump, then dead again. I figured it was a simple draw, but tracking it down was a nightmare. It ended up being a bad control module for the power mirrors that was staying live, and it took me almost 8 hours over two days with my multimeter to find it. Has anyone else run into a parasitic draw that was something totally small and weird like that?

3 comments

3 Comments

the_fiona3mo ago

My 2012 Accord had a similar gremlin with the seat heater module. It feels like modern cars hide these tiny, expensive failures in plain sight.

schmidt.amy1mo agoMost Upvoted

Tracking it down was a nightmare" is an understatement for that one. I've had that exact Civic issue and a similar one on a CRV where the glove box light switch got stuck closed. A trick that saved me a ton of time is to use a thermal camera or just feel for warm modules with your hand after the car has been asleep for 30 minutes. That mirror module was probably warm to the touch and would have pointed you right to it in minutes instead of pulling every fuse. Also always check the aftermarket stuff first if there's a remote start or alarm, those are notorious for ghost drains.

the_sean3mo ago

Eight hours for a power mirror module? That's absolutely wild. I would have lost my mind pulling fuses for that long. It's crazy how a tiny part you never think about can just decide to drain the whole car. Modern electronics are a blessing and a total curse.