MRCARTOOL B550 Automotive Circuit Tester With LED Display
$129.99 Original price was: $129.99.$109.99Current price is: $109.99.
- Comprehensive Circuit Diagnostics: Seamlessly test DC voltage, resistance, and diodes in one go. The built-in Multimeter Mode automatically identifies circuit conditions for rapid, error-free troubleshooting.
- Precision Component Activation: Apply a positive or negative battery current to test lights, cooling fans, and relays without jumper wires. Choose from Moment, Latch, or Pulse activation modes for tailored testing.
- Advanced Sensor Simulation: Features a 0-5V adjustable power supply and an Oscilloscope Mode to evaluate sensor signals (like MAP sensors) and verify ECU wiring integrity with ultimate precision.
- Buy with Confidence: Backed by our official 2-year manufacturer warranty, ensuring your investment is fully protected against manufacturing defects.
- Online Support>>
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MRCARTOOL B550 Automotive Circuit Tester is designed specifically for diagnosing vehicle electrical systems, assisting professional technicians and DIY enthusiasts in testing 9 to 30-volt circuits swiftly and accurately. By conducting battery current directly to the probe tip, it allows users to effortlessly determine circuit polarity, check continuity, and activate components on the spot. Featuring an upgraded 2.4-inch TFT color screen, oscilloscope mode, and 0-5V sensor simulation, the B550 delivers rapid, pinpoint electrical diagnostics in one streamlined tool.
What is the difference between all MRCARTOOL Automotive Circuit Tester?
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MRCARTOOL B530 Automotive Circuit Tester With LED Display
Rated 5.00 out of 5 based on 20 customer ratings$69.90
MRCARTOOL B550 Automotive Circuit Tester Features
- Smart Multimeter Integration: Quickly cycle through functional interfaces using the 4-key navigation pad. Test DC Voltage (0.1V-100V), Resistance (1Ω – 200KΩ), and Diode Continuity all on a vibrant 2.4-inch true-color LCD.
- 0-5V Sensor Power Supply: Diagnose tricky ECU wiring issues by simulating sensor voltage outputs. You can easily adjust the power supply from 0 to 5 volts (with current limited under 100mA) in 0.5-volt increments to safely test sensitive electronic components.
- Oscilloscope & Hertz Testing: Go beyond basic probing. The B550 displays frequency, duty cycle, max/min voltages, and real-time waveforms (like sine or square waves) to accurately verify signal circuits such as MAP sensors.
- Customizable Component Activation: Power up electrical components on the spot with three activation modes: Momentary, Latch, or Pulse. To prevent wire melting, the internal circuit breaker’s overload current can be manually adjusted from 1A to 18A.
- Overload & Short-Circuit Defense: The system is continuously monitored by an internal circuit breaker that trips automatically if the current exceeds your set limit, acting as a crucial safety measure to protect both the tool and the vehicle.
- 2-Year Quality Guarantee: We proudly stand behind our automotive tools. Enjoy worry-free operation with a standard 2-year warranty covering your entire order.
Packing List :
| Weight | 1.1 kg |
|---|---|
| Dimensions | 18 × 25 × 8 cm |
| Ship From |
22 reviews for MRCARTOOL B550 Automotive Circuit Tester With LED Display
| 5 star | 95 | 95% |
| 4 star | 4 | 4% |
| 3 star | 0% | |
| 2 star | 0% | |
| 1 star | 0% |
Customer Images










Tomasz Sudol
This tool is essential for mechanics, offering a range of functions that make diagnosing and analyzing car issues easier. It's particularly helpful for detecting leaks that could drain the battery and is versatile enough for other repairs and designs. The tests are straightforward, all performed directly with the probe. The device is simple to operate with just one button to power it on, and another to navigate the menu, select the language, and choose the measurement mode. It can measure diodes, resistors, power, voltage, and even display signal waveforms in real time. With its impressive 10+ meter long cable, you have plenty of flexibility to move around the car and perform tests from various angles—whether connected to the battery or using the cigarette lighter socket. The backlit color display makes reading clear even in bright conditions, and the tool comes with everything you need, including a convenient carrying case. It's so user-friendly that you won’t even need the instructions. Highly recommend it for anyone needing reliable, portable, and easy-to-use diagnostic equipment!

Hilary Josh
Funciona bien, se siente de burna calidad y sus opciones de funcionabilidad son muy buenas.

Joy Timothy
It's worth mentioning that the first one I bought had a problem with another buyer, but I liked the software, so I decided to buy it here, and it's definitely a wonderful product.

Ruth Augustine
Отличный прибор, крайне востребованный в своей нише

Ruth Augustine
Отличный прибор, крайне востребованный в своей нише

Enid Leacock
This MRCARTOOL circuit tester is a fantastic product—its flashlight function is perfect! It has multiple modes (DC voltage, resistance, oscilloscope) and an adjustable output voltage of 0-5V, which is sufficient for all my automotive circuit tests. I especially like its multilingual support and two-year warranty. Customer service also responded quickly. Highly recommended!

Luther Chapman
Many of my customers purchase this product at our small shop. Though it's a small item, it makes a big difference. My clients say it helps them troubleshoot car battery issues on their own, saving them a lot of time and repair cost

Destin Bailey
Nice device like it was described

Monte Ziemann
Workmanship like norms will be tested!









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MRCARTOOL B550 Automotive Circuit Tester With LED Display
Q & A
MRCARTOOL B550 Automotive Circuit Tester With LED Display








I’ve been using the MRCARTOOL B550 for a while now, and it works great. The voltage reading is accurate, and the LED display is clear and easy to read. It quickly helps me check polarity, power, and ground without any hassle. The build quality feels solid, and it has made electrical diagnostics much faster and easier. Definitely a reliable tool for anyone working on automotive electrical systems. Highly recommended!
A really useful piece of kit to have in the garage. Well made and easy to use to troubleshoot electrical problems.
Tendo em conta o preço/qualidade ideal para verificação no automóvel, grande ferramenta.
This tool is essential for mechanics, offering a range of functions that make diagnosing and analyzing car issues easier. It’s particularly helpful for detecting leaks that could drain the battery and is versatile enough for other repairs and designs. The tests are straightforward, all performed directly with the probe.
The device is simple to operate with just one button to power it on, and another to navigate the menu, select the language, and choose the measurement mode. It can measure diodes, resistors, power, voltage, and even display signal waveforms in real time.
With its impressive 10+ meter long cable, you have plenty of flexibility to move around the car and perform tests from various angles—whether connected to the battery or using the cigarette lighter socket.
The backlit color display makes reading clear even in bright conditions, and the tool comes with everything you need, including a convenient carrying case. It’s so user-friendly that you won’t even need the instructions.
Highly recommend it for anyone needing reliable, portable, and easy-to-use diagnostic equipment!
Ist nicht schlecht aber Ideal wäre wenn anstelle die Spitze bannen Stecker anschließen zu können. Ideal für Hobby schrauber für Kleinigkeiten.