Stray wire near battery

330 Views 6 Replies 4 Participants Last post by Wahobbert, 2 mo ago

Greengrape22

Discussion Starter · 3 mo ago

Yesterday I put a new battery in my car. I noticed a wire that was not connected near the battery with the end broken off.
The person helping me said it was after market (but didn’t know what for)

Does anyone know what this wire is for and if I should have it fixed? Seems like I should be using all the wires under there lol
2012 Passat TDI 2.0L

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Wahobbert

· #2 · 3 mo ago

It seems pretty obvious that it used to be on the pinch bolt on that negative battery clamp. Grab a crimp lug that goes over the bolt and reattach it...

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Greengrape22

Discussion Starter · #3 · 3 mo ago

Thank you!

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AndreasPassat

· #4 · 3 mo ago

I'm going to err on the side of caution here. Seeing owner installed wiring like that makes me shiver. You never know what genius work the previous owner did.
If everything on the car functions as it should I would leave it disconnected until it's determined what that wire was supplying power to.
If the wire is there to make a factory device function, well then, the real problem should be diagnosed and fixed properly.

Maybe for an aftermarket radio memory, who knows. But if that were the case they should have just ran a short fused wire from the Terminal 30 buss connection under the dash.
See where I'm going with this?

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Greengrape22

Discussion Starter · #5 · 3 mo ago

AndreasPassat said:
I'm going to err on the side of caution here. Seeing owner installed wiring like that makes me shiver. You never know what genius work the previous owner did. If everything on the car functions as it should I would leave it disconnected until it's determined what that wire was supplying power to. If the wire is there to make a factory device function, well then, the real problem should be diagnosed and fixed properly. Maybe for an aftermarket radio memory, who knows. But if that were the case they should have just ran a short fused wire from the Terminal 30 buss connection under the dash. See where I'm going with this?

I’ve discovered more wires. The blue grounds to the frame and there is also a red wire that it disconnected.

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Timberto

· #6 · 3 mo ago

I find this all the time. Usually it's a amateur installation of radio or subwoofer or alarm running on power from the positive terminal. Odd to see and aftermarket wire to ground direct to battery but who knows.

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Wahobbert

· #7 · 2 mo ago

It's pretty obvious that it's a ground since it's on the negative side, and with the stretched crimp lug it couldn't possibly reach anywhere else but the negative battery terminal/ lug. You could always do a continuity check on it to see if it has continuity to ground if you wanted to be absolutely sure.

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