Topdon CT100 | Circuit tester
Warranty directly via AsTools
Warranty directly via AsTools
We handle warranty cases ourselves, quickly and without involving the manufacturer. Thanks to our own parts inventory and technical expertise, we can usually assist you immediately. Only in exceptional cases do we still send the product to the supplier.
2 years warranty on all products
2 years warranty on all products
All our products come with a 2-year factory warranty. This ensures you long-lasting quality and service.
Easy returns
Easy returns
You can easily request your return through your account. We will send you the return label by email. Return shipping costs are your responsibility.
Professional customer service
Professional customer service
Our experts are ready to help you quickly and professionally, both online and in our physical store. Questions? Feel free to contact us!
The Topdon CT100 is an automotive circuit tester for diagnosing electrical problems in vehicles. The device features a bright digital display with backlighting that shows DC voltage within a range of 3.3 to 65 V, with a resolution of 0.1 V. Additionally, the tester performs a professional load measurement up to 1.2 A, checking battery load and circuit load to detect aged batteries, weak connections, and voltage drops. Thanks to the wide measurement range, the tester is suitable for 12V, 24V, and 36V systems in cars, trucks, and campers.
When contacting a circuit, the tester immediately shows the polarity via two-color backlighting: red for positive and green for negative, supported by ± indicators on the screen. The extended 3.8-meter (12.5-foot) test cable reaches hard-to-access places without moving the tester. Through the universal 4mm banana plug connections, interchangeable probes and clamps can be used. The tester works without a battery thanks to power from the circuit being tested, with built-in protection against overvoltage, overheating, and reverse polarity to protect sensitive vehicle electronics.
ADVANTAGES
HIGHLIGHTS
Applications and functionalities
The CT100 supports the following electrical test functions:
- DC voltage measurement: Measures DC voltage from 3.3 to 65 V with 0.1 V resolution for checking batteries, sensors, and power supplies.
- Load test: Draws up to 1.2 A from the circuit to assess actual load capacity and reveal weak points.
- Polarity check: Shows immediately via red or green backlighting whether a connection is positive or negative.
- Fuse test: Checks continuity and voltage on fuses without removing them from the fuse box.
- Wiring diagnosis: Traces breaks, shorts, and voltage drops in vehicle wiring.
- Connector check: Verifies voltage on connectors and plugs when troubleshooting starting issues or intermittent faults.
Package Contents
- 1x Topdon CT100 Circuit Tester
- 1x 2mm probe
- 1x Crocodile clip
- 1x Adapter
- 1x Storage bag
- 1x Quick start guide
Technical specifications
| Specification | Description |
|---|---|
| Product brand | Topdon |
| Product model | CT100 |
| Voltage measurement range | DC 3.3 V to 65 V |
| Load measurement | 5 V to 30 V (Max. 1.2 A) |
| Measurement accuracy | 3.3 V to 60 V: ±0.1 V / 60 V to 65 V: ±0.2 V |
| Measurement resolution | 0.1 V |
| Cable length | 3.8 m (12.5 ft) |
| Probe connection | 4 mm banana plug |
| Operating temperature | -10 °C to 50 °C (14 °F to 122 °F) |
| Storage temperature | -20 °C to 70 °C (-4 °F to 158 °F) |
