Step 2: Connect the battery clamps to the vehicle battery. Red clamp to the Positive Polarity (+), Black clamp to Negative Polarity (-). The green illumination of the Correct indicator shows that the jump starter is ready for jump-starting. Just by correctly connecting the clamps to the terminals, the JS1500 delivers a jump to the vehicle battery. Step 3: Try starting the vehicle. If it fails, disconnect the battery clamps from the vehicle's battery and wait for 20 seconds, then reconnect and try again. It's recommended not to attempt more than 3 consecutive jump starts within 2 minutes. 12