Please help me figure out what's wrong with my 09 Lancer Sport

2009 Mitsubishi Lancer sport, with Rockford Fosgate sound system.

Above are a couple of short videos showing the issues I am currently having with my Lancer. Be sure to check the description of the YouTube videos as there are additional details about the issue.

About three months ago I ran into a dead battery, and I thought it was just that. I replaced set battery at approximately four weeks later I again came across a dead battery. I had the battery tested and it failed, so I again had it replaced. 2 weeks later the battery was dead again and I had the [alternator] tested by 2 different shops in the mean time. The alternator passed both times.

Yesterday I walked out to start my car, and it started showing the symptoms outlined in the videos. Is there anybody out there that I can explain what could cause such an issue?

The only thing I can think of is there’s a short in a wire somewhere.

I didn’t go to YouTube or listen to the video BUT…

What you describe in your text is a classic parasitic draw problem caused by your sound system. Both OEM and aftermarket systems suffer from this problem. They age, they develop an internal short and they draw the battery down over a day or 2 or 3 and cause a dead battery.

Pull the fuses for you head unit and power amps, if any, and see if the problem goes away. Put them back in and see if it comes back. If it does, you have found the overall cause. Test just the amps, or just the head unit to narrow it down. Replace the bad unit.

Concur w/advice above, good chance of something remaining powered on & draining current when vehicle isn’t being used. Sound systems and security systems are common culprits, esp if aftermarket. Shop can do parasitic drain current test to know for sure, should be 50-75 mA or less.

If you want to do something yourself and know how to work a DVM, the battery should measure about 12.6 volts before the first start of the day. Immediately after starting the engine, 13.5-15.5 volts. Is your vehicle within those voltage ranges?

I bought one and started pulling fuses. turns out there was a Bluetooth module that wasn’t even hooked up to anything or used whatsoever powering on. I’m just gonna leave that fuse out.

thanks for the reply.