What is the TopDiag P50?

The TopDiag P50 is a professional-grade automotive circuit tester designed for diagnosing and troubleshooting electrical issues in vehicles. It operates within a DC voltage range of 5V to 30V, making it compatible with most modern cars, motorcycles, and trucks.

This tool is commonly used by auto electricians, mechanics, and technicians to test:

• Fuses

• Light sockets

• Connectors

• Wires

• Relays

• Other 12V/24V vehicle electrical systems

Its transparent body provides visibility into the operation, and the internal LED indicator gives immediate feedback when voltage is detected.

How Does the TopDiag P50 Work?

1. Connect the Alligator Clip to Ground:

   • Attach the clip to a clean, unpainted metal surface on the vehicle (usually the chassis or engine block). This completes the electrical circuit.

2. Touch the Probe Tip to the Test Point:

   • Touch the metal tip to the fuse, socket, wire, or electrical component you want to test.

3. Observe the LED Indicator:

   • If voltage is present at the test point, the LED inside the transparent body will light up.

   • If the LED does not light up, it means:

     • There's no voltage at the point

     • The circuit may be open

     • The fuse might be blown, or there could be a wiring issue

4. Interpret the Results:

   • Light ON = Power is present (circuit is live)

   • Light OFF = No power (possible issue)

Advantages:

• Fast and easy to use — no need for multimeters in many cases

• Transparent body improves visibility in low-light areas

• Compact, pen-like design fits easily into toolkits

• Suitable for both 12V and 24V vehicle systems