DUOYI DY18 Car Circuit Tester is a comprehensive 6V–24V DC automotive circuit tester designed to speed up electrical diagnostics. Unlike a basic test light, it allows you to actively power components and perform advanced continuity tests without needing additional jumper wires.
Active Power Injection: By rocking the power switch forward or backward, you can conduct a positive or negative battery current directly to the probe tip to activate components like fans, fuel pumps, or window motors.
Instant Continuity Testing: Use the probe tip along with the auxiliary ground lead to test switches, relays, diodes, and fuses for continuity.
Short Circuit Tracking: Helps you follow and locate short circuits without wasting fuses. If the internal circuit breaker trips, you've found the overloaded or shorted branch.
Polarity Identification: Quickly identifies if a circuit is positive or negative. The LED indicator typically turns Red for positive (+) and Green for negative (-).
Safety Protection: Features an internal overload protection (8A breaker). If the current exceeds 8A, the unit automatically disconnects to protect the tool and the vehicle's electronics.
| Feature | Details |
| Operating Voltage | 6V – 24V DC |
| Cable Length | Approximately 4 meters (13 feet) |
| Overload Protection | 8A (Automatic cut-off) |
| Indicators | Bi-color LED (Red/Green) and Audio Buzzer |
| Dimensions | 220mm x 20mm |
Polarity Test: Connect the clips to the battery. Touch the probe to a wire; Red LED = Positive, Green LED = Negative.
Component Activation: To power a motor or light, touch the probe to the positive terminal and rock the power switch forward (+).
Continuity: Use the auxiliary ground lead in tandem with the probe tip. If the LED lights up Green, the circuit is continuous.
Caution: Do not use this tool on 110/220V household AC currents or on sensitive electronic control units (ECUs) that operate on very low voltage, as the direct battery current may damage them.
