Can anyone tell me what these screw threads are from? Under the right side of the passenger seat (US).

No sign of a bolt head under the car.

I’ve used one of them as an amplifier ground, and am experiencing corrosion issues.

thanks.

 

Those studs are to mount a factory CD changer. I don’t see any corrosion issues in the attached picture.

 

How big of an amp are you running? That stud is a bit dainty for the size ground cable you're using if your amp is taking full advantage of the cable.

 

In the picture attached I’d cleaned up the connection and refitted. The corrosion happens inside the terminal where the copper strands meet the connector. It’s the copper that corrodes.

The amp case was also screwed to the floor, and that suffered also…. Pic.





Also I noticed the seat mount has a decent level of rust. Possibly not connected.




Amp was quite substantial, 1200w. But that’s the one that died. I since replaced with it a 600w version, same brand. Although I’m never really pushing the system. It’s pretty terrible. Need new door speakers all around.

I wondered if it could be some kind of electrical induced rust. Like I know boats have a sacrificial material so the corrosion eats that and not the boat.

 

You could try bolting up some zinc there! I think that rust is typical. Seen it in every single junk yard D2. I dont think there is much of a seal between those holes and the outside. I would also seal up the holes with larger washers and silicone or something else. I need to get that area buttoned up myself.

Boats use zinc all over, the zinc goes first.

I have been zinc plating bolts I take off before re-installation if time permits. it takes about 30 min once you get a strong solution.

 

Pretty certain what is happening is that your carpet is getting damp, the foam under the carpet is staying damp, and causing this corrosion over time. The amp case and seat bracket is a dead giveaway. I'd pull the carpet, focus on water ingress testing.

 

that… is a very good thing to check.

thanks.