- Description
LCD-Backlit Automotive Circuit Tester Pen (AC/DC 3-300 V, Continuity & Resistance)
4-in-1 Diagnostic Power
Automatically detects AC/DC voltage, resistance, and continuity, plus stores your last value—ideal for fast checks on fog lights, fans, relays, or fuse circuits.
Backlit Display & Probe LED
Green backlit LCD with 0.1 V resolution remains readable in direct light; hold the 💡 key to illuminate dark fuse boxes or engine compartments.
Nickel-Coated Steel Probe
The precision-ground metal spike pierces insulation cleanly and seats firmly into terminals—delivering accurate readings every time.
Extended Reach & Easy Battery Access
With a 59-inch elastic lead, you'll access any hood or footwell. Slide the rear cover to replace a single AAA cell in seconds—no tools needed.
Pocket-Friendly & Workshop Tough
At just 7.5 × 1 × 0.9 in and 0.24 lb, this tester fits your glovebox or gear bag. EVA pouch included to keep everything tidy on the go.
Specifications
| Voltage Range | 3 – 300 V AC/DC (auto-detect) |
| Resolution | 0.1 V |
| Resistance Range | 0 – 9.99 MΩ |
| Continuity Alert | Beep + icon (<50 Ω) |
| Display | 4-digit green backlit LCD |
| Cable Length | 11.8 in (relaxed) to 59 in (extended) |
| Probe Material | Nickel-plated steel |
| Power | 1 × AAA battery (not included) |
| Ingress Rating | IP40 (dust & splash resistant) |
| Weight | 0.24 lb / 110 g |
FAQ
Q 1 | Will it harm my car’s electronics?
No—the probe draws under 2 mA and is designed with polarity protection for ECU safety.
Q 2 | Is it compatible with 24V systems?
Yes—fully supports 6V, 12V, and 24V systems up to 300V.
Q 3 | How do I choose between AC and DC?
No need—the tester auto-detects voltage type and displays the correct mode.
Q 4 | What does the “HOLD” button do?
Freezes the current reading so you can view it even when the screen is out of sight.