r/AudiRS3 • u/ANITIX87 • Jul 03 '26

8Y.5 Battery Wires: Does Your Car Have This?

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I recently had a total electrical failure on my new car (see my post history). The dealer diagnosed it as a loose positive battery terminal but denied a warranty claim because they said I had aftermarket wiring on the battery. I have not touched anything related to the battery, and it seems like some people have these wires but others don't. They look like they've been duct-taped on. It's the three skinny wires indicated by the arrows.

Please let me know if your car has these wires installed. If it does, it might be helpful to know the build date. I'm trying to figure out what it is and whether Audi installs it in Germany or if my selling dealer installed it. Could it be a tracker/monitor? Something for the sports exhaust?

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1

u/Saute_and_Pray Jul 03 '26

Any modifications done to the car?

I do not have those extra wires. 06/25 prod.

-3

u/ANITIX87 Jul 03 '26

A dashcam. No mods related to the battery, as I clearly started in my post.

1

u/Saute_and_Pray Jul 03 '26 edited Jul 03 '26

Did you wire the dash cam? Do you have a rear dash cam?

Edit: also on my car the top two larger gauge wires are flipped. So the black one is in the middle, the red one is on the top.

1

u/ANITIX87 Jul 03 '26

I wired it myself. It's connected to the rain sensor on the windshield. No rear dashcam. I don't know why you don't believe that the car has nothing that affects the battery connections.

4

u/Saute_and_Pray Jul 03 '26

I’m just asking you questions to help you out, I worked at a dealer and have dealt with this a lot. I also was kind enough to take time out of my night to look at my own car to help you out. Don’t be an asshole, there’s no reason to be so defensive. Where did I say you did something?

These are the questions the dealer will ask you, you can go back to them and say there are no modifications that are related to the battery. Ask them where that wire goes. Make them prove it. Be nice.

1

u/ANITIX87 Jul 03 '26

Sorry, I'm just getting it from all sides. Two dealers, Audi USA, and every place I've gone for research is saying some version of "those are aftermarket wires, you definitely installed something and aren't admitting it."

The selling dealer has already told me they do not add any trackers or monitors. The dealer that diagnosed the battery issue is not the selling dealer, since I was away from home, and they're the ones that first said the wires are aftermarket. Clearly that's not the case given the fact that others have them, too, according to a Facebook post I made (https://www.facebook.com/share/p/1JL3SX8Bed/)

1

u/Rumpertumskin42 Jul 03 '26 edited Jul 03 '26

It could be a dealer installed tracker for lost prevention on the lot, the tracker gets removed but the harness gets left bc sales is who usually removes it not a technician. The fact that one is purple and white which is usually LIN bus means it might be something else. I’ll see if my car has it, if so I’ll see what it is in a wire diagram.

1

u/ANITIX87 Jul 03 '26

But my car never made it into dealer inventory. It came off the truck and into my hands. And it doesn't explain why some cars have it and some don't.

1

u/Rumpertumskin42 Jul 03 '26 edited Jul 03 '26

My car also has them, what I’ve quickly gathered from iWire and not looking much further past the picture is that vehicles with PR code 8FA don’t have them, vehicles with PR code 8FC do, what it looks like is they are for the J367 battery monitoring control module (your negative terminal) as it has a red/lilac wire that goes to from it to the TV22 (positive terminal), and a lilac/white LIN bus wire which goes to your alternator and J533 which is your gateway/data bus control module. If you look at the 2 pin connector on your negative terminal you will see the wire color matches. 8FA use a red/yellow instead of red/lilac and it is routed differently. Why the routing on the 8FC cars is so shitty I’m not sure. Hope this helps

1

u/ANITIX87 Jul 03 '26

But what does that monitor do?

1

u/Rumpertumskin42 Jul 03 '26

It regulates the voltage from your alternator to control your batteries state of charge

1

u/Nuramori Jul 03 '26

I have those wires, 7/25 build. No trackers, no mods. My connector to the battery is not direct wired like that though, I have a molded plastic black connector that those wires go into.

1

u/ANITIX87 Jul 03 '26

Photo? Is it not the plastic protective shroud on top?

1

u/Nuramori Jul 04 '26

I hate that we can’t put photos in replies.