Hi all,

I have a 2007 tC and about a year ago I started experiencing battery issues. At first I thought I needed a new battery, so I replaced it, but the battery kept dying after only a couple days without driving. So I took it to a mechanic and they did a parasitic draw test and told me it was the radio fuse that was drawing too much power from the battery when the engine was off. I have since confirmed this by disconnecting the fuse--the car can go for over a week without a dead battery. The mechanic told me they couldn't fix it and suggested I take it to the dealership. I did this, but the dealer basically just tried to scam me into getting a new alternator (the alternator is fine). They refused to even acknowledge the problem.

So I have yet to find anyone who can fix this issue. I replaced the radio, thinking this may fix the problem, but it did not. I also disconnected the satellite radio receiver, but that did not work either. Has anyone else experienced this?

A couple additional notes: I had a stock radio before replacing it, and I have a sub that was dealer-installed. Any and all advice would be appreciated.

 

With that fuse in does the amplifier stay on all the time even when the car is off? If so then the amp is installed wrong, the turn on lead was hooked up to the radio constant power.

 

Thanks for the reply. How would I know if the amp is on when the car is off? I don't really think the amp was installed wrong, since I have owned the car for about 8+ years and just started having this problem in the past year or so...

 

It just occurred to me that about a year and a half ago, shortly before I noticed the issue, I had to get a tail light replaced that was blocked by the subwoofer. This required the mechanic to remove the sub, replace the light, then reconnect it. Could this be what caused the battery drain?

 

As long as the bulb was replaced correctly no it shouldn't. It's easy to check the amp to see if it is on, there will be a light on it that will be lit up.

 

So I couldn't find the amp (maybe I don't have one?), but there was a green light on the subwoofer that remained on with the engine off.
Seems like I found the source of the battery drain, now the question is how to fix it. I suppose I will take it to a mechanic soon.

 

The amp is part of the sub in your case. If you can take a picture of the wiring going to it I can probably tell you what is hooked wrong.

 

Sounds like they re-wired the sub wrong when they replaced it after the tail light fix. Probably just need to relocate a power wire.