Hellomy girlfriend hasa 2003 Audi A4 quattro. I need to replace the battery but I notice that there is a separate cable that runs off the top of the battery, down the firewall towards the driver's side and appears to go into the cab of the car, behind the vacumm box. This wire is separate from the positive and negative wires. Is it a vent tube, or does it run something else? I just was going to replace it with a battery from Auto Zone, but wanted to make sure this wire does not run some other function. I have extensive experience on American cars, but little on Audi's so any help is appreciated. Also do I need the battery back 9v back up to change the battery, or can I do it without it? And where do I find the radio unlock code, as the battery is dead and when I jump started it, the radio was in safe mode.

 

Welcome to the forums!!

I don't have any idea about the battery, but the radio code should be on a card in the owner's manual. If you post this over in the A4 forum, I'm sure you'll get your questions answered. It sees a lot more activity than the new New Member forum does.

 

Thank you.