prem

Hi There,

My A8 was garaged for few weeks, today when I tried to take it for a spin, I was surprised, car didn't respond to key in ignition, no sound, no nothing.

Things observed:

1) Remote key-less fab entry - Worked only for the first time.

2) Dash light came on when I inserted the key, but started dimming while trying to crank

3) There was EPC light on the dash, along with battery light and Extended beeping sound to go with it.

4) After few unsuccessful tries, the dash light went out completely and no beeping sound, no nothing as of now.

Symptoms suggest dead battery - Thinking of jump starting the car, not sure which is the positive and negative terminal in this car. Because the red wire which is suppose to mean positive but red wire is connected to negative terminal and black which is suppose to be connected to negative is connected to positive terminal. Also not sure which terminal is grounded.

Secondly, In the owners manual, it says connected negative to negative but in all the videos I saw, all of them warn against connecting directly to negative terminal of the dead battery, instead recommending to connect to the metal part of the car for ground. Please clarify.

Attaching the picture, Kindly advice.

the_duke

That is a brown wire on the negative terminal. You might think about cleaning the corrosion off of the positive terminal. Follow the directions in your owners manual.

prem

LoL is that brown... no wonder I'm color blind . Yeah thought about the corrosion but it was working fine with corrosion till few weeks ago, anyhow will clean that up. btw which terminal is grounded, how to find that out ?. Thanks.

Duke, Thanks for the reply.

prem

Confirmed, It is it dead battery. Yest after reaching home, Cleaned the positive terminal and connected neg to neg as mentioned in the manual (which is contrary to popular belief as it might cause spark and fire) .... Car started to respond.

Thanks.

silverd2

Maybe I also just fell off the turnip truck, but why (unless the photos lie) is there an electrical wire connected to the battery acid overflow tube ?

Pushbutton_auto

Ok, good some pics,

Now what is that brown wire and where does it connect (floating aimlessly on my S8).

Also I have what I thought was just a batt breather pipe, but today I see there are two similar pipes, one with a wire running thru it, and connected to the positive terminal.

the pipes I refer to are the black ones left of last pic.

Pushbutton_auto

nobody ?

jfrahm

There is a sunroof drain in that area. No idea what the brown wire is for, have you looked at the wiring diagram?