ANCEL 1224V Automobile Battery Circuit Probe Tester 1. Display: 1.77-inch TFT (160x128 DPI) 2. External power supply: 12 or 24V power supply is provided through the vehicle battery 3. It has short circuit protection function. If the load is too large, its internal circuit breaker will trip This circuit breaker is not only a useful test tool, but also a safety measure to protect the tool from overload damage. 4. When the circuit breaker trips, all other functions of the tool are still in normal working state, which means you can still detect the circuit and observe the voltage readings. When the circuit breaker trips, the tool cannot conduct battery current to the probe even if the power switch is pressed. Intentionally tripping the circuit breaker and using the tool for detection can be considered an additional precaution to prevent accidental pressing of the power switch. 5. There are four modes for diagnosing electrical systems, which can be entered by pressing the "Mode Button" and switching in turn. 6. DC voltage: When using this tool in this mode, the probe tip is contacted with the circuit, and the LCD display will then display the DC voltage value with an accuracy of 0.1V 7. AC voltage: When using the tool in this mode, the probe tip is contacted with the circuit, and the LCD display will then display the voltage and frequency. 8. Resistance Test: When using this tool in this mode, the probe tip is contacted with the circuit, and the LCD display will then display the resistance value between the tip and the auxiliary ground wire. 9. Diode: In this mode, the probe tip contacts the positive electrode of the diode, connects the auxiliary ground wire to the negative electrode of the diode, the screen will display a forward voltage drop, indicating a forward bias. If the position of the probe tip and auxiliary ground wire are exchanged, the screen will not display a voltage, indicating a reverse bias. Voltage and Polarity Test: When the tool is in DC voltage mode, contact