I was doing some electrical wiring on a snowmobile trailer today and was surprised to see black instead of shiny copper when I cut and stripped a section from the middle of a long section of uninterrupted wire. There was literally at least 5m of uninterrupted wire on either end of where I cut!
My questions are as follows:
- Can wire oxidize INSIDE the protective rubber? I know wires exposed to air oxidize, but this is literally meters down a rubber-coat wire...
- And if so, is the wire still good to use or should I be ripping it out and redoing all the wiring on my trailer?
- I'm assuming simply crimping it without at least cleaning it will introduce a lot of electrical resistance, and potentially melt my crimp connector?
For context: wire is 18 AWG copper; used for simple trailer wiring - running current from the vehicle 4-pin connector to the trailer lights. I'm from the PNW, so it is pretty wet around here, and the trailer does see a lot of winter driving on salty roads. Here are a few pictures:
You can see two of the oxidized wires at the top, I included a new/fresh wire for comparison.
The oxidation can be rubbed off with the edge of a knife, but it's not ideal - seems to be really easy to damage/brake off the copper strands.
Any thoughts? Suggestions?