Battery keeps dying after sub install

[ShadowTrooper]

I was too lazy to do the powered sub install myself (JBL BassPro Hub) when I had the tint installed, so I just had the shop do it while they already had it for the day. Well, shortly after, I got a FordPass notification that the car went into deep sleep. About 30 days later the battery died. This was an EverStart Walmart battery that I’d replaced in Jan of 2024, so it shouldn’t have died this quickly…I suspect some kind of faulty wiring on the sub amp - possibly no remote line connected? However, I did see that after about 30 sec of the car being turned off and doors locked, the lights on the wired controller connected to the powered sub would turn off. Figured everything was fine and maybe it was just a bad battery…Fast forward to last week when I swapped the battery with a new one from Costco. Everything seemingly working fine until just about an hour ago I got another FordPass notification that remote features were being disabled to preserve battery life…sounds like the amp/sub may indeed be wired incorrectly, and not properly turning off.

Question for those who’ve installed an aftermarket amp: is there a remote line on the stock B&O amp that can be tapped? I’d assume the installer would have connected it, but searching in some past posts, the only thing I can see in the pinout diagram are power/ground, and speaker level outs. I’d go out and look, but it’s near freezing outside and I don’t really want to be out there ripping apart cold panels and possibly snapping clips unnecessarily if someone can share. Thanks in advance for any info!

 

[UNBROKEN]

A lot of newer integration stuff uses an auto-sense feature to turn on amps and such…or it could be a simple wire to a switched 12V source. There’s no remote out wire off the oem system.
You should have a fuse for the new stuff somewhere. Just pull that and see if your issue goes away.

 

[ShadowTrooper]

Thanks for the reply. I think I may have figured it out. I jumped the car, scanned the modules and found B1533-08, referencing an issue with the Headlight Control Module. I noticed I wasn’t able to turn the headlamps on/off (they were on by default, prob last setting), and there were no LEDs lit on the control module itself. The trunk release worked fine, but the dial, fog button, and dashboard illumination buttons wouldn’t work at all. I tried unplugging the module, turning the car off and restarting the engine, pulling the fuse, but nothing changed. The headlamps wouldn’t turn off after I tried locking the car, so I pulled the negative lead on the battery, waited 10 sec and reconnected it. After that, the light on the control module lit up, and I was able to use the buttons.

This kind of all makes sense, considering the other day I was parking the car, it was turned off, and when I went to open the door, it started to chime like something was on, but I didn’t think to look at the headlights. I did turn the dial, but nothing changed, so I didn’t bother. Just figured it was a temporary gremlin.

When I parked the car last night, the lights did turn off though, so I’m assuming something is wrong with the control module, and it needs to be replaced. Coincidentally, I Googled and found this has happened to a few other people too. All things considered, it’s a $70 part that swaps out in 2 sec, so I just went ahead and bought a new one and hopefully won’t run into this issue again, at least for a while.