Recently I’ve had quite a bit of work done on my 05 TL and ever since I bought it almost 2 years ago there’s been a random tube/ fuse (I don’t know the term) that’s connected to my + battery terminal. I had my heater core flushed a couple weeks ago because my heat would blow cold and I just looked under my hood and found the tube disconnected and a wired wrapped in electrical tape. One of ends of the wire leads to a box with “PA66-GF30” on it that is behind the engine. After googling it has something to do with a radiator but I was wondering if anyone knew what it was for. I’ve have not noticed any functional difference to the car and how it drives, If I didn’t just replace my upstream o2 sensor I probably wouldn’t have noticed that it was disconnected. I’ve attached some pictures in case someone might be able to help me identify what these parts/tube might be. Any info helps! Thanks.

 

The previous owner of the car had a sub/amp in the trunk, and the big red wire is the power wire for the amplifier. You should just disconnect the wire completely at the battery terminal, cuz eventually electrical tape can wear through.

 

that clear 'tube' is an aftermarket fuse holder