We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Handheld 6-24V DC circuit tester with digital display and extended probe cable

OnRetul CT03 6-24V DC Circuit Tester with Digital Display 3.5-36V

SKU CH-CFX0-D18RA

Tests 6-24V DC automotive circuits with 3.5-36V digital display and overload protection

  • Team affiliation1 Piece
  • Key featuresManual, Corded Electric, false
  • Overall height1.5 L x 1.3 W x 9 H inches
  • Overall width1.5 L x 1.3 W x 9 H inches
  • Overall length1.5 L x 1.3 W x 9 H inches
  • Tests 6–24V DC circuits with digital 3.5–36V readout
  • Identifies polarity and continuity in one handheld tool
  • Extra-long cable reaches full vehicle without blind spots
  • High-sensitivity probes cut troubleshooting time by 50%
  • Overload protection safeguards tool and circuit under test

Professional Automotive Circuit Tester

The OnRetul CT03 is a new DC circuit tester built for 6-24V vehicle systems. It measures voltage, verifies polarity, checks continuity and locates short circuits or poor grounds. The tool suits professional mechanics and DIY enthusiasts working on 12V and 24V battery systems.

Verify Vehicle Voltage Before Use

Confirm the vehicle runs on a 12V or 24V DC battery system; the tester is not suitable for AC power or voltages above 36V. The digital display reads from 3.5V to 36V, so ensure the circuit under test falls within that window. The extended cable reaches front-to-rear, but check that the probe can access the test points in your specific vehicle.

Low Heat and Silent Operation

The corded electric design draws minimal power from the circuit itself, so the body stays cool during normal use. No fan or moving parts are present, keeping operation completely silent. Overload protection guards the tool and the vehicle wiring if a fault exceeds the rated range.

How it compares

Measured against everything we stock in Multimeters & Electrical Testers, at today’s prices. Recalculated every night.

Price $22.99
Cheaper than about 70% of the 971 comparable items (median $30.99).

Specifications

Product
Brand nameOnRetul, OnReTul
Size & build
Overall height1.5 L x 1.3 W x 9 H inches
Overall width1.5 L x 1.3 W x 9 H inches
Overall length1.5 L x 1.3 W x 9 H inches
More details
Team affiliation1 Piece

Questions about this item

What comes in the box with the OnRetul CT03 and do I need to buy anything else to start testing?

The package includes one tester unit with its integrated digital display and extended detection cable. No separate probes or leads are required; the tool is ready to use on 12 V and 24 V vehicle systems straight out of the box.

Should I choose a different model if I only work on 12 V cars versus 24 V trucks?

The same CT03 covers both 12 V and 24 V battery systems because its measurement range spans 3.5 V to 36 V DC, so a single unit handles passenger cars and light commercial vehicles without needing a second tester.

What does the 3.5 V to 36 V display range mean when I am probing a live circuit?

The screen will show real-time DC voltage anywhere between 3.5 V and 36 V, letting you verify battery health, locate voltage drops, and confirm polarity on both 12 V and 24 V systems, but it will not read AC mains or voltages above 36 V.

More in Multimeters & Electrical Testers

Similar items