JFIND JF107 – Relay Tester for Car & Motorcycle (12/24 V, 4-5-pin)

Specifications

• Product Name: JFIND JF107 Automotive Relay Tester
• Function: Relay tester for 4- and 5-pin relays
• Voltage Range: 12 V / 24 V (vehicle use)
• Model: JF107
• Relay Types: 4-PIN (30/85/86/87), 5-PIN (30/85/86/87/87a) – standard mini/ISO layout
• Indication: Status LED/display for coil pull-in, NO/NC switching, deviation
• Protection: Basic protection against polarity reversal and short transient spikes
• Usage: Bench or vehicle test (external 12/24 V power supply via battery)
• Target Group: Automotive enthusiasts, workshops, field troubleshooting

Features & Applications

• Quick Relay Check: Detect coil breaks, burnt contacts, sticky armatures, and incorrect pin layouts.
• 12 V & 24 V: Suitable for passenger cars, light trucks, some construction machinery, and motorcycle applications.
• 4/5-pin Support: Testing of NO/NC switching (87/87a) on 5-pin relays.
• Indicator Logic: Visual feedback for pull-in and contact switching during load simulation.
• Time-Saving: Avoid unnecessary relay replacement by chance – test and confirm the fault first.
• Wide Range of Applications: Fuel pump, fan, AC clutch, lights, glow plugs, auxiliary relays, etc.

Compatibility

The JF107 is designed for standardized mini/ISO relays with pin designations 30, 85, 86, 87, 87a. Supports both 12 V and 24 V. Special relays (micro relays, solid state, time relays, or OEM-specific with non-standard layouts) may require other methods and are not always supported by this tester.

Manual & Step-by-Step

1) Safety & Preparation

1. Work with the ignition off and in a ventilated environment. Wear safety glasses.
2. Identify the relay's pin layout (embossing on the relay casing): 30 (common), 85/86 (coil), 87 (NO), 87a (NC).
3. Connect the tester to the correct supply voltage (12 V or 24 V) from the vehicle's battery or lab power supply.

2) Connect the Relay

1. Place the relay in the tester's 4- or 5-pin socket according to the marking.
2. Ensure the relay is inserted straight and fully seated – crooked insertion can lead to incorrect readings.

3) Run the Test

1. Select the correct voltage mode (12/24 V).
2. Start the test. The tester excites the coil (85/86) and monitors switching between 87/87a.
3. Follow the indicators: "Coil OK/Fail", "Switch NO/NC OK/Fail", possible warning for abnormal condition.

4) Interpretation & Action

• Coil not pulling in: Coil break or incorrect voltage mode. Measure coil resistance, verify 12/24 V selection.
• Pulls in but does not switch: Worn/burnt contacts or mechanical sticking – replace relay.
• Intermittent: Vibration/temperature-sensitive relay – recommended replacement.

5) Completion

1. Turn off the tester and disconnect the power supply.
2. Pull the relay straight out. Label defective relays for traceability.

Troubleshooting & Interpretation

• Tester does not start: Check polarity and that the supply voltage matches the selected mode (12/24 V).
• Relay clicks, but the load does not work in the car: Check in the vehicle – fuse, wiring, ground point, socket in the fuse box.
• "OK" on the bench, but fault in operation: The relay may fail under heat load/vibration – replace with a quality relay and check current requirements.
• 5-pin test: Confirm that 87a (NC) breaks when the coil pulls in and that 87 (NO) closes.

Frequently Asked Questions (FAQ)

1. Does the JF107 support both 12 V and 24 V?

Yes. Select the voltage mode that matches the relay/vehicle before testing.

2. Can I test any relay?

The JF107 is designed for standard 4/5-pin ISO relays. Special/solid-state/time relays may require other equipment.

3. Is it a battery tester?

No. It is primarily a relay tester. It shows the supply status during the test but does not replace a complete battery/charging test.

4. Can I test the relay without removing it from the car?

It is recommended to remove the relay and bench test it for safe and repeatable measurement.

5. What do the pin numbers mean?

30 = common load, 87 = normally open (NO), 87a = normally closed (NC), 85/86 = coil (polarity usually does not matter for mechanical relays).

Tips & Best Practices

• Label relays: Keep functional ones as reference, clearly label defective ones.
• Check load current: A relay can "click" but still fail under high current – replace with the correct current rating.
• Clean sockets: Oxidized relay sockets in the car can cause heat and voltage drop.
• Heat test: Suspect intermittency? Gently heat/cool and test again.
• Complement diagnosis: For fault code reading and live data – see our handheld scanners.

Package Contents

• 1 × JFIND JF107 Relay Tester (12/24 V)
• 1 × Quick Guide/User Manual
• — External power source/clamps may be required (not included depending on package)

Important Notes & Disclaimer

• Only for DC 12/24 V. Do not use on other voltage levels.
• Test removed relays to avoid unintentional short circuits in the car.
• Always follow the vehicle manufacturer's service procedures. All use is at your own risk.
• The relay's rated current and type must correspond to the vehicle's specification before reassembly.

Summary

The JFIND JF107 is a reliable, fast, and simple solution for verifying 4- and 5-pin relays at 12/24 V. Its clear indication and support for both NO/NC tests make troubleshooting efficient – whether for fuel pumps, fans, lighting, or other critical auxiliary circuits. An essential part of every toolbox. 🔧