Heat: The positive terminal can get hotter than the negative terminal, which can also contribute to corrosion. The negative battery terminal is the black cable connection. While it’s less prone to corrosion than the positive terminal, it can still be affected. Here’s what to look for:
Both the negative and positive battery cables are vital for the vehicle’s electrical system. The simplest way to tell the positive cable from the negative cable is by looking at their color. Positive battery cables are red and larger as they give power to the electrical system for starting the engine and other vehicle accessories.
When the positive battery cable is damaged, your alternator won’t achieve full charge giving your a low voltage battery. A normal car battery voltage reading is 12.6V when the vehicle is off and between 13.7V to 14.7V when your vehicle is running.
Sulfation: Lead sulfate, a common component of battery corrosion, tends to form more readily on the positive terminal. Heat: The positive terminal can get hotter than the negative terminal, which can also contribute to corrosion. The negative battery terminal is the black cable connection.
Over time the vapor from the hot engine operation corrodes the battery terminal, causing a buildup resulting in increased resistance which can block current flow. Corrosion can seep into the cable, corroding it on the inside. The best remedy is to replace the battery cables. This is one of the bad negative battery cable symptoms.
Run the new negative cable like before and place it on the negative battery terminal. Use a wrench to tighten the terminal end. Also, slide the positive cable over the positive terminal to attach it to the battery. Use a wrench to tighten the terminal end, then reattach your negative terminal and tighten until it is snug.