Does anyone know of any common Key off-Engine off power drains on '05-09 Mustangs?

[Fullboogie]

I know it's an old thread, but my '07 GT500 came with the crappy Shaker 500 and I always have had battery drain problems. I spent hours doing proper load tests and never could ID any circuit that was causing it. Installed an aftermarket (Pioneer) head unit and it still does it. I hate having to keep the car on a trickle charger - it's the one thing I hate about this car.

 

[ghunt81]

That sucks. Mine was good up until a few years ago- I never added any electrical equipment during that time so I don't know what the issue is. I just have to disconnect the battery if the car is gonna sit for more than a week which generally isn't a big deal.

 

[DieHarder]

That sucks. Mine was good up until a few years ago- I never added any electrical equipment during that time so I don't know what the issue is. I just have to disconnect the battery if the car is gonna sit for more than a week which generally isn't a big deal.

Mine is the same but I have replaced the map bulbs w/LED's so that's likely the source in my case. Stock stereo and like you I have to disconnect the neg cable of the battery to prevent batt drain. The problem has killed two batteries over the last few years. Got a digital charger to keep the battery conditioned. So far, so good.

 

[ghunt81]

I've had LED's in my map lights since probably the second year I owned my car and I've had it for 12 years, so I dunno. Those draw so little current I can't imagine them draining the battery but who knows.

Now that I installed a new head unit I would be curious to see if it's better but I don't want to draw the battery dead again, I had to replace it a couple years ago because of that.

 

[ghunt81]

So, been awhile but I wanted to update this for anyone else who might come across it. Over the winter I pulled out the original Shaker 500 head unit with the integrated CD changer (the radio looked terrible plus I had a sneaking suspicion the changer was killing the battery) and replaced it with a Jensen touchscreen with bluetooth, Apple Carplay and Android Auto. Over the course of the summer I have experienced no slow starts or anything even after sitting 3-4 days, so apparently I was correct on the CD changer drawing power even when off!