About This

Power Up Diagnostics with Confidence – Apply 3V, 5V, 12V, or 24V to activate components & test fuses, relays, circuits, and more. Identify faults fast with this pro-grade voltage tester.
Multifunction Testing in One Tool – Combine fuse tester, relay tester, continuity checker & power supply probe in one compact device built for mechanics & automotive electricians.
Patented 45° Swivel Head for Easy Access – The 5420’s angled swivel probe pivots 45 degrees to reach tight spots and awkward connectors you couldn’t with a straight probe; ideal for under dashboards, inside fuse boxes, and cramped engine bays.
Instant Results, Bright Display – Large 1.25" backlit LCD and LED polarity indicators clearly show voltage, continuity, or shorts—even in low light. Spark plug & circuit machine ready.
No Guesswork, Just Clarity – Trigger components directly & see if they respond, so you pinpoint faulty relays or switches without removing them. Save time and second guesses.
Rugged Safety Features Built In – Integrated 10 MegOhm circuit breaker prevents overloads. DC capable, compatible with all common car diagnostic tool needs.
Built for Heavy-Duty Use – Durable 20ft cable handles garage abuse, while 10 MegOhm input impedance ensures safe testing on sensitive circuits. Perfect for automotive tools kits.