TOPDON CT100 Automotive Circuit Tester, 5-30V Professional Load Testing, Measurement Range: 3.3V-65V, Accuracy up to ±0.1V, 12.5 ft Extends

The TOPDON CT100 automotive circuit tester, with professional 5 to 30V load testing and a measurement range of 3.3V to 65V accurate to 0.1V. The lead extends to 12.5 feet, and it suits trucks, saloons, SUVs, motorcycles and motorhomes at up to 1.2A DC.

Specifications

• Measurement range: 3.3V-65V
• Supported Models: Trucks, Sedans, SUVs, Motorcycle, RV
• DC: 5-30V Max: 1.2A

What you get

• 1pc x TOPDON CT100 Main Unit
• The CT100 is a professional automotive circuit tester built for speed and accuracy. It helps diagnose electrical issues, identifies polarity, and provides clear alerts. Built rugged with a long cable and interchangeable probe, it works on various vehicles. Fast, precise results for pros and DIYers.
• TOPDON CT100 Automotive Circuit Tester
• 5-30V Professional Load Testing
• Accuracy up to ±0.1V
• Why Choose TOPDON CT100?
• Versatile Compatibility & Extended Reach
• Compact, Lightweight, Easy to Use
• The CT100 is compact, lightweight and easy to carry for everyday diagnostics. The 12.5-foot extended test lead gives you greater reach without constantly repositioning, while universal 4 mm banana plugs support DIY accessories and compatibility with most standard probes and clips.
• The built-in professional load test function supports DC 5-30V circuits with up to 1.2A output and activates with a simple press-and-hold monitors real-time voltage drop to help identify weak batteries, poor connections, and internal circuit faults, enabling fast, accurate, and reliable diagnostics for automotive electrical systems.
• Precise Voltage Measurement
• The CT100 measures 3.3-65V DC with dependable accuracy across a broad range of automotive electrical systems. It delivers ±0.1V accuracy from 3.3-60V and ±0.2V accuracy from 60-65V, helping technicians diagnose circuits, batteries, and electrical components with greater confidence.
• The CT100 automatically detects positive and negative polarity using color-coded backlight indicators(red for positive connection, green for reverse connection) and clear ± symbols on the display. This instant visual confirmation helps prevent reverse connections and protects sensitive vehicle electronics during testing.
• Clear Digital Voltage Readout
• The high-contrast digital display shows real-time voltage and polarity clearly. The 0.1V resolution readout delivers direct, accurate data at a glance for fast, intuitive diagnosis.
• Distinct audible alerts indicate startup status, reverse connection warnings, active load testing, and overvoltage or overheating conditions, allowing technicians to monitor circuit status without checking the display.
• Color-coded backlight indicators confirm polarity instantly, while additional alerts display overvoltage ("H"), overheating ("Hot"), and lamp abnormality ("ER1") status, keeping key operating conditions visible at a glance during testing.
• Built for a Wide Range of Automotive Electrical Tasks
• Vehicle electrical system testing, battery condition checks, circuit troubleshooting, and basic wiring diagnostics
• Daily electrical inspections, load testing, fault detection, and routine vehicle maintenance support
• Circuit principle demonstrations, polarity identification training, voltage measurement practice, and hands-on learning.

A load test tells you whether a circuit can carry current, which a voltmeter alone never shows.

Orders leave the warehouse within one business day. Delivery then takes 7 to 20 days. Orders over $150 ship free.

Not right for you? You have 30 days from delivery, with no restocking fee. See the full returns policy.