On the car battery, the positive wire is red and the negative wire is black. If the body of the car is metal or conducts electricity, then the body of the car serves as the negative wire. The metal in the engine serves as the negative wire.
Black
Negative - (Black) is Ground, Positive + (Red) is Hot. Ground wire goes to Negative (Black) it goes from negative on battery to engine for ground.
BLACK
get a multi meter that reads dc voltage & touch the black (negative -) wire to the negative battery post & the red (positive +) wire to the positive battery post with car running. car off is battery voltage, car on is alternator voltage.
disconnect the negative (black) first then positive (red).
there is not a proper grounding wire mounted to the body of the car or truck.
The black wire means negative and the red wire means positive if that's what you where asking
Hook positive up first, negative last.
Normally red or brown. The battery has a + stamped into it by the positive terminal. Follow the wires, on a modern car the positive will go to the alternator and starter. The negative wire (easier to follow) will go to the body/engine block
The electrode with the + mark, red wire. Black is negative.
Car Radio Battery Constant 12v+ Wire: Orange Car Radio Accessory Switched 12v+ Wire: Yellow Car Radio Ground Wire: Black Car Radio Illumination Wire: Gray Car Stereo Dimmer Wire: Brown Left Front Speaker Positive Wire (+): Tan Left Front Speaker Negative Wire (-): Gray Right Front Speaker Positive Wire (+): Light Green Right Front Speaker Negative Wire (-): Dark Green Left Rear Speaker Positive Wire (+): Brown Left Rear Speaker Negative Wire (-): Yellow Right Rear Speaker Positive Wire (+): Dark Blue Right Rear Speaker Negative Wire (-): Light Blue