What is this black wire on the positive terminal for?
#3
A previous owner ran it to power something. I usually try to use either red or yellow wires for power supply. I'd say it's for a relay that is switch operated since it's on the positive terminal. Your cables are both with replacement connectors. You're going to have electrical problems down the road from corrosion. Take them both apart and clean them good and put some dielectric grease on the wires. Clean the battery terminals and grease them too. I've run the clamp style terminal connectors before, often for years. I generally will just replace the cables with good ones as the other end is often not much better.
#5
A previous owner ran it to power something. I usually try to use either red or yellow wires for power supply. I'd say it's for a relay that is switch operated since it's on the positive terminal. Your cables are both with replacement connectors. You're going to have electrical problems down the road from corrosion. Take them both apart and clean them good and put some dielectric grease on the wires. Clean the battery terminals and grease them too. I've run the clamp style terminal connectors before, often for years. I generally will just replace the cables with good ones as the other end is often not much better.
#6
A previous owner ran it to power something. I usually try to use either red or yellow wires for power supply. I'd say it's for a relay that is switch operated since it's on the positive terminal. Your cables are both with replacement connectors. You're going to have electrical problems down the road from corrosion. Take them both apart and clean them good and put some dielectric grease on the wires. Clean the battery terminals and grease them too. I've run the clamp style terminal connectors before, often for years. I generally will just replace the cables with good ones as the other end is often not much better.
#7