I’m often getting asked, “Do I need new cables?” I’m always puzzled by the question since I can’t lift the hood and inspect the old ones by email.
However, there are a few things to look for that are dead giveaways that it’s time for new cables!
Cracks in the insulation are points where acid can enter and attack the wire. If they haven’t started corroding yet, you can pretty much bet that they will eventually.
Cables can burn from contact with headers or other exhaust components. If the cables are undersized they can quickly get very hot especially during extended or excessive cranking. Sometimes they get so hot that the insulation actually melts or burns. Also look for insulation that is misshapen or deformed from melting and then cooling into its new shape.
Those 99-cent, bolt-on battery terminals are junk. Use them in an emergency but replace them as soon as possible. It’s hard to get a good connection and the exposed copper strands are a welcome invitation for corrosion.
Electrical issues are much harder to find that physical issues. You can’t always just look at the wire and tell if there’s an electrical problem. If the wire is getting hot during cranking, it probably has a hidden defect or is undersized.