12V Automotive Relay Tester – 4 & 5 Pin LED Indicator

Universal 12V Automotive Relay Tester with LED Indicator

Take the guesswork out of diagnosing electrical faults in your vehicle. This compact automotive relay tester (model CNBJ-707) connects directly to your 12V car battery and performs a thorough go/no-go check on the most common 4-pin and 5-pin automotive relays — giving you an instant GREEN or RED LED result in seconds.

Made in Mainland China.

Why You'll Love This Relay Tester

• Quick Pass/Fail Results: GREEN LED = relay passed; RED LED = relay failed or pin mismatch. No guessing, no multimeter math.
• Supports 4-Pin & 5-Pin Relays: A simple selector switch lets you test either relay type across three receptacle sockets.
• 10-Cycle Contact Test: The tester automatically opens and closes the relay 10 times to verify contact closure speed, opening time, and overall consistency.
• Direct Battery Power: Powered by your car's existing 12V battery (11V–15V range) via colour-coded alligator clips — no separate power source needed.
• LED Power Indicator: The unit lights RED when powered on so you always know it's ready to test.
• Compact & Portable: Slim enough to toss in your glovebox or tool bag for roadside or workshop use.

How to Use

1. Clip the black alligator lead to the battery's negative terminal and the red lead to the positive terminal. The LED will illuminate RED to confirm power.
2. Identify your relay type (4-pin or 5-pin) and set the selector switch accordingly.
3. Plug the relay into one of the three receptacle sockets on the tester.
4. Press the TEST button.
5. The tester verifies pin configuration, cycles the relay contacts 10 times, and checks consistency. GREEN LED = pass; RED LED = fail.
6. Disconnect the alligator clips and remove the relay when done.

Specifications & Attention Notes

• Compatible voltage: 11V – 15V (standard 12V automotive battery)
• Ideal for relays with coil resistance above 20 ohms
• Tests 4-pin and 5-pin automotive relay configurations
• LED indicators: RED (power on / fail), GREEN (pass)
• No batteries required — powered directly from the vehicle battery

Package Contents

• 1 × Car Relay Tester (CNBJ-707)

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Frequently Asked Questions

Q: Which relay types does this automotive relay tester support?

A: The CNBJ-707 relay tester supports the most common 4-pin and 5-pin automotive relays. A selector switch on the unit lets you choose the correct configuration before plugging in and testing your relay.

Q: Does the relay tester need its own batteries or power supply?

A: No separate power supply is needed. The tester draws power directly from your vehicle's 12V car battery (operating range 11V–15V) through the included colour-coded alligator clips, making it ready to use anywhere your car is parked.

Q: What do the LED indicator colours mean on this relay tester?

A: When connected to the battery, the LED lights RED to show the unit is powered and ready. After pressing the TEST button, a GREEN LED indicates the relay passed all checks (pin configuration, contact timing, and consistency). A RED LED indicates the relay has failed one or more checks or has an unrecognised pin layout.

Q: What coil resistance is recommended for accurate relay testing?

A: For best results, use this tester with automotive relays that have a coil resistance of 20 ohms or higher. Relays with very low coil resistance may not produce accurate go/no-go results.