Quick Picks:
Best Relay Tester Reviews:
SaleBestseller No. 1 
Relay Buddy 12/24 Volt
- Tests both 12V and 24V relays
- 3 diagnostic trouble codes help define the cause of the bad relay
- Quick off-the-car relay tester
- Checks relay coil & switch contacts
- Fails bad relays - Good/Bad indication, green light for PASS, red light for FAIL with flashing trouble code
Bestseller No. 2 
Electronic Specialties 193 Black 2.5" x 5" 12/24V Diagnostic Relay Buddy Pro Test Kit
- Tests 5 different relays, both 12V and 24V and 3 diagnostic trouble codes help define the cause of the bad relay
- Kit Includes 5 Relay Adapters and blow mold case
- Quick off-the-car relay tester
- Checks relay coil & switch contacts
- Fails bad relays - Good/Bad indication, green light for PASS, red light for FAIL with flashing trouble code
Bestseller No. 3 
Lisle 69300 Master Relay Test Jump Set
- Includes 8 Jumpers to fit most popular relays
- Includes Test Lead Kit for easily and securely connecting Relay Test Jumpers to a multimeter
- Terminal Leads with switch, fuse and power options provide easy access to check current or voltage on many fuses and relays used on vehicles today
- Also allows testing of relay configurations not covered by eight Relay Test Jumpers, like Volkswagen, BMW and other European vehicles
- Relay Puller Pliers easily remove electrical relays; weorks without piercing wires
Bestseller No. 4 
Relay Buddy Electronic Specialties 191 Pro Test Kit
- Kit includes Relay Buddy tester, 5 new relay adapters and blow mold case
- Relay Buddy is a quick go/no go tester for the most common automotive relays
- With the included adapters, Relay Buddy now tests 5 different relay types and also tests shielded relays
- Relay Buddy will fail the relay and light the red LED if any of the test cycle proves unsuccessful during the test session; green light if relay is good
- Settable to 4 and 5-pin relay and uses vehicle's 12 volts battery for power
Bestseller No. 5 
Electronic Specialties Super Relay Buddy Pro Kit
- Improved test finds bad relays effectively
- Full 7+ amp load flags intermittently failing relays
- Three test results - Green/Pass, Red/Fail & Yellow/Pass with caution
- Wider test coverage with included adapters, checks 10 different 12 Volt relays
- Fully automated, 10 cycle test verifies the condition of the relay
Bestseller No. 6 
LEQUDUO 9038 Relay Tester, 9038 Diagnostic Scan Tool Fuel Pump Relay Bypass Master Kit, Pack of 6, Plastic
- These relay bypasses are great for electrical diagnostics, they help save a good amount of time in terms of narrowing down what could be wrong on a car. A must have for any mechanic's toolbox.
- Installation is pretty simple: just plug in the place of the fuel pump relay and direct control over the fuel pump circuit is realized in most domestic, Japanese, Korean and German applications. They can be mounted horizontally or vertically and stainless steel mounting screws are attached with panel, which can make the switch panel installed firmly based on your needs.
- Package includes 6 pieces of relay bypasses
Bestseller No. 7 
Lisle 60150 Relay Pro 12V and 24V Relay Tester
- A straightforward relay tester that will easily and quickly test most 12 and 24 volt DC automotive relays
- Tests relays by simply clicking the test leads onto the relay terminal pins using a 12 or 24V DC power source
- Automatically determines how the relay coil and contacts are configured
- This eliminates the need for specific tester footprints or adapters
Bestseller No. 8 
Lisle 56820 Relay Test Jumper, Yellow
- Set of four relay test jumpers make testing relays or live circuits quick and easy
- Simply remove relay to be tested, insert correct jumper and insert relay into jumper
- No need to pierce wires or connect multiple jumper wires
- For more information check the main Lisle tool- 56810
- Replacement part for Lisle tool- 56810
Bestseller No. 9 
Electronic Specialties Super Relay Buddy
- Improved test finds bad relays effectively
- Full 7+ amp load flags intermittently failing relays
- Three test results - Green/Pass, Red/Fail & Yellow/Pass with caution
- Greater coverage, tester alone checks 7 different 12 Volt relays
- Fully automated, 10 cycle test verifies the condition of the relay
SaleBestseller No. 10 
TopDiag P200 Automotive Circuit Tester, Power Circuit Probe Kit, 9~30V with Multimeter/Relay/Fuel Injector Tester/Activating Component/0~5V Power with 20ft Cable for 12V 24V Vehicle
- 💪【Powerful Circuit Tester Kit】The P200 Automotive Circuit Tester is the only circuit tester on the market that can be upgraded, a tool for quickly testing all ✅9V-30V✅ electronic systems. It can diagnose problems in the components, electrical circuit systems or fuel injectors of the car in the shortest time. Not only the test time is greatly shortened, but also more intelligent and intuitive, suitable for any novice driver or maintenance engineer.
- 💪【Fuel Injector & Relay Tester】It is extremely important to regularly test the fuel injector. Damage to the fuel injector can easily lead to unstable idle speed of the engine, increased fuel consumption, causing engine shock. It is worth mentioning that TopDiag P200 auto circuit tester has been added 300+ USD valued powerful functions, namely: ✅Fuel Injector Test✅ Relay test mode. TopDiag makes diagnosing your car easier and saves maintenance costs.
- 💪【0~5V Adjustable Power Supply & Activating Components】0~5V power is useful when checking the wiring to the ECU/ECM, also meet the voltage requirements for the sensitive parts with low voltage. Besides positive activation, negative activation is our newest function which others none, power on components at a moment notice.
- 💪【Smart Test & Positive & Negative Test】When connected to the probe of Car Electrical Test Tool to measure voltage, resistance, positive/negative polarity, it will automatically become an instant auto-range, intelligent judgment does not require manual selection, and the corresponding parameter values and prompts are displayed on the HD LCD screen. With a 20ft cable, you can quickly assist you in diagnosing the car's condition without opening the wiring.
- 💪【Multimeter & Oscilloscope Tester】The P200 Circuit tester will be the more versatile and powerful Power Circuit Probe Kit you've ever seen. Contains the multimeter's DC voltage (VDC), resistance (OHM), diode/on-off test (DIO), current (AMP) and frequency test functions, combined with the unique oscilloscope function and buzzer, can test components according to voltage, resistance value, frequency duty cycle, and waveform diagrams to quickly diagnose problems with your circuit system.
Bestseller No. 11 
Cal-Van Tools Relay Circuit Diagnostic Tool 12-24
- This tool gives the technician the ability to instantly determine the problem within a tested circuit. It will identify at the push of a button if a wire a part or a relay is defective without the use of a multi-meter.
- The tool also features easily accessible ports for use with other diagnostic tools.
- Since the item can jump the relay the technician can use it as a remote control starter in engine work like compression testing distributor or cam shaft adjusting or to run the compressor during an A-C charge.
- Kit includes the tester 6 popular relay leads 1 universal relay lead.
- Works with both 12 and 24 volt systems.
SaleBestseller No. 12 
KAIWEETS Voltage Tester/Non-Contact Voltage Tester with Dual Range AC 12V-1000V/48V-1000V, Live/Null Wire Tester, Electrical Tester with LCD Display, Buzzer Alarm, Wire Breakpoint Finder-HT100 (Red)
- SAFETY FIRST: It will send out multiple alarms through sound and light. When the voltage is detected, the tip will send out red light and beep. When the higher the sensed voltage is, or the closer it is to the voltage source, it beeps at a higher frequency. At the same time, the screen will be red or green, red means high voltage and live wire are detected, green means low voltage and null wire are detected.
- NON-CONTACT: With NCV inductive probe for AC voltage; Just place the tip near a terminal strip, outlet, or supply cord. When the tip glows red and the pen beeps, you know there's voltage present. The live wire detector can automatically detect the live or neutral wire. Ideal for breakpoint Test. Handy circuit tester for electricians, homeowners.
- DUAL RANGE: Detects standard and low voltage (12-1000V AC / 48-1000V AC) for more sensitive and flexible measurements. Press the S button to adjust sensitivity and adapt low range for doorbells, thermostats, irrigation wiring etc.; The NCV sensor automatically recognizes the voltage and displays it on the bar graph.
- SECURITY LEVEL: IEC rated CAT III 1000V CAT IV 600V, Meets CE requirements; The electrical tester is safely double insulated. High Voltage Alert to warn you of voltage above 90V, the screen turn red and the safety symbol on the screen shines.
- COMPACT DESIGN: Bright LED flashlight for work in dim ares; Low-Power-Indicator when battery voltage is below 2.5V; Automatic Power Off after 3 minutes without operation or signal detection; Pocket-sized, pen hook allows you to carry it in your shirt pocket. We provide 36-Month after sale service, Please feel free to contact us if you have any concerns.
SaleBestseller No. 13 
Power Circuit Probe Kit, Electrical System Tool Short Tester Car Fuse Relay Automotive Circuit Tester Fuel Injector Tester&Cleaner Breaker Finder Tracer Tool with 20Ft Cable for 6-30V Vehicle
- 🚘【MOST PRACTICAL CIRCUIT TESTER】With the GT103 probe tester, you can test for continuity/polarity/voltage and ground signals/Short&Open Circuit. And most importantly, you can also use it to check switches, relays and the on-off of diodes, fuses and circuits, activating electronic Component. It is the best electrical tester for reducing diagnostic time in all 6-30 volt vehicle electrical systems.
- 🚘【PORTABLE AND QUICK TEST ELECTRICAL TESTER】With the GT103 car circuit tester tool, you can determine at a glance whether a circuit is positive, negative, short or open; Test for continuity with its built-in auxiliary ground lead; can also easily test the vehicle's headlights, turn signals, lift windows, sunroofs and others, helping you to find out whether it is a circuit problem or a component damage.
- 🚘【CAR FUEL INJECTOR TESTER & CLEANER】Free DIY Injector Cleaning Adapter Kit included with the package! When the vehicle has difficulty in starting, acceleration and fuel consumption, etc, it is necessary to check the fuel injector. When the injector is clogged, you can also use it to save expensive nozzles, this kit is easily to clean most car motorcycle fuel injectors. Efficient & Labor-free, Save your money!
- 🚘【20FT LONG TEST LEAD】The GT103 Circuit Tester features a long 20-foot (6m) cable that allows you to test from the front to the rear of the vehicle (trucks, trailers, vessels, tractors and other vehicles that use DC circuits) without constantly searching for suitable vehicle grounds, so easy to check the whole electrical circuit system.
- 🚘【CIRCUIT OVERLOAD PROTECTION】The GT103 Circuit Tester provides more safety for the user because it is protected by a 10-amp circuit breaker. If overloaded, it will trip and automatically disconnect the protection circuit. The circuit breaker is a valuable test tool as well as a safety measure to protect the tool from overload and make the product more durable.
SaleBestseller No. 14 
GODIAG GT101 Power Circuit Probe Tester, 4 in 1 Circuit Tester, Fuel Injector Tester and Cleaner, Relay Tester, Current Detection with Overload Protection, Working Voltage Range 6V/12V/24V DC
- 【4 in 1 Multi-function Power Circuit Probe Tester】This automotive power circuit probe has multiple functions. It supports circuit voltage test & current detection, relay testing, circuit break finding, fuel injector cleaning and testing, etc. Working voltage range 6V-40V, support variety vehicles. This power circuit probe tools includes English instruction manual for your convenience!
- 【Excellent Function & Quick Diagnostics】This automotive electrical system test tool is the perfect choice for automotive circuit probe tester. Unlike other circuit testers that require you to use a variety of tools to troubleshoot electrical system problem, our circuit testers are perfectly capable of performing multiple types of services such as continuity testing, component activation, fuse test, checking bad ground indicator, detect voltage and current, positive and negative power supply.
- 【Positive and negative power supply】When the vehicle's headlights, turn signals, lift windows, sunroofs and other functions fail, our power circuit probe kit can output positive and negative power to check whether circuit components are normal, and can also perform continuity checks and resistance checks. Through these checks and diagnoses whether the path of the car circuit is interrupted, it can be found which parts of the circuit are intact, which parts are bad.
- 【Fuel Injector Tester & Cleaner, Relay Tester】This car power circuit probe tester tool covers the detection of fuel injectors and relays, as well as the cleaning of fuel injectors. When the vehicle has difficulty in starting, acceleration and fuel consumption, etc, it is necessary to check the fuel injector. When the car's headlights, turn signals, horn and the engine starter do not work, and there is no problem with these components after detection, you can check the relay switch.
- 【20ft Extension Cable & Flashlight】Our circuit tester contains 20ft/242inches long cable, which provides excellent accessibility to test along the large vehicles such as trucks, buses, engineering vehicles, vessels, tractors, mining vehicles and other vehicles that use DC circuits. Moreover, it has a built-in flashlight that will illuminate your work area even at night.
Bestseller No. 15 ![TopDiag P200 Power Probe, (2022 Newest) 9V 30V Circuit Tester Automotive w/ Power Feed Testing, Fuel Injector Test, Relay Test, Activating Components,AC/DC Voltage Measurement [Online Upgrade]](https://m.media-amazon.com/images/I/41+FXstKL2L._SL160_.jpg)
TopDiag P200 Power Probe, (2022 Newest) 9V 30V Circuit Tester Automotive w/ Power Feed Testing, Fuel Injector Test, Relay Test, Activating Components,AC/DC Voltage Measurement [Online Upgrade]
- 【ABOUT P200 Car Circuit Tester】The 2022 Newly Upgraded generation of intelligent P200 automotive circuit tester is the only circuit board tester on the market that can be upgraded, a tool for quickly testing all 9V-30V electronic systems. It can diagnose problems in the components, electrical circuit systems or fuel injectors of the car in the shortest time. Not only the test time is greatly shortened, but also more intelligent and intuitive.
- 【Double Automatic Circuit Breaker Protection】Using short-circuit automatic protection function and 20amp fuse fuse, when it encounters overload, its internal overload protection system will automatically open circuit or power off protection.
- 【Multimeter & Oscilloscope Tester】The P200 Circuit tester will be the more versatile and powerful Power Circuit Probe Kit you've ever seen. Contains the multimeter's DC voltage (VDC), resistance (OHM), diode/on-off test (DIO), current (AMP) and frequency test functions, combined with the unique oscilloscope function and buzzer, can test components according to voltage, resistance value, frequency duty cycle, and waveform diagrams to quickly diagnose problems with your circuit system.
- 【0~5V Power Supply Mode and "SET" Overload Current Setting】The power supply circuit probe can set 0-5V output voltage and 1A~8A current to detect the circuit connection and ensure the safety of the tested equipment.
- 【Smart Test & Positive/Negative Test】When connected to the probe of car electrical test tool to measure voltage, resistance, positive/negative polarity, it will automatically become an instant auto-range, intelligent judgment does not require manual selection, and the corresponding parameter values and prompts are displayed on the HD LCD screen. With a 20ft cable, you can quickly assist you in diagnosing the car's condition without opening the wiring.
Last update on 2023-02-08 / Affiliate links / Images from Amazon Product Advertising API