If you own a car, having the best automotive test lights available is a must-have. It will easily help you do troubleshooting to evaluate the fuse’s condition, check the brake light, find grounds, and check the condition of the alternator, among many other things.

Though the same job can be done by a voltmeter or multimeter, using a test light is more convenient as it has a long, sharp piercing probe that can easily touch the testing surface. A voltmeter or multimeter is best used when you need deep troubleshooting.

Best Automotive Test Lights

In this buying guide, we will explore the five best automotive tester lights that you can find on the market. We’ll cover the specifications and everything you need to know to make an informed decision to suit your needs.

1. EFORCAR Circuit Tester

This is a circuit tester that can work for both 6V, 12V, and 24V DC systems. It is a great tool that can help you detect power, ground, or wall to find any shorts or wire breaks. They are small in size, making them portable and compact. It has a rack that makes it easy to carry and use.

The tool can be used in various machinery maintenance operations such as in automobiles, motorcycles, bulldozers, etc. This automotive test light has been made in a way that is easy to use.

Product Information

  • Package Dimensions: 10.8 x 3.7 x 0.2 inches
  • Product Weight: 2.11 ounces


  • It can do both 6V, 12V, and 24V DC systems
  • The test light can be used in different settings
  • It is portable and compact
  • It is easy to use
  • The tester is safe and insulated


  • It does not work well on a 24V system

2. SourceTon Professional Circuit Tester

This comes as a pack of two testers. Professional testers can be used to detect an open circuit, fuse signal light, etc. It supports a wide range from 6V to 24V DC. Cars, RVs, and trucks can use it.

The automotive test light has a high-quality build made with copper and plastic to ensure that it is safe. It is characterized by a long probe along with an alligator clip to ensure you can easily access the hard-to-reach places.

Product Information

  • Package Dimensions: 10.8 x 8.2 x 2 inches
  • Product Weight: 9.6 ounces


  • It comes as a set of two in a pack
  • The tester can be used in a wide variety of settings from 6V to 24V
  • It is reliable and durable thanks to the material used
  • The tester is safe


  • Some users complained of poor quality

3. OTC 3634 Heavy-Duty Straight Cord Circuit Tester

This automotive test light is specifically designed to test electrical circuits and identify any short grounds and open circuits.

It is efficient in checking both 6V and 12V DC systems. When you buy it, you get a 5-foot heavy-duty cord to ensure that it lasts you a long time. The handle of the tester is slim and ergonomic with a bright replaceable bulb.

The handle also features a contact-molded strain relief so that it is comfortable to use.

Product Information

  • Product Dimensions: 3.35 x 9.55 x 1.75 inches
  • Product Weight: 0.035 ounces


  • It can be used for checking both 6V and 12V circuits
  • The tester comes with a long heavy duty 5 feet cord
  • The handle has a replaceable bulb
  • It has a slim, ergonomic, and comfortable handle


  • Some users complained that they got a shorter cord than expected

4. TOPEMAI 3-48V Digital LCD Display Circuit Tester

Unlike many automotive testers, this one has an LCD display to make your work easier.

It is a heavy-duty tester that can be used in a wide range of applications as it can be used from 3 – 48V circuits. You can use it to test circuits in different settings.

The LCD display enables you to have an accurate voltage read, which is essential if you are into the details. The testing pen is needle-sharp and made of stainless steel so that you can easily pierce any surface if you need to.

The automotive tester is small and lightweight, with an ergonomic design that can access confined areas. It has a long cable length of 11ft, making it convenient for you to use it well.

Product Information

  • Product Dimensions: 3.2 x 0.6 x 0.2 inches
  • Product Weight: 7.5 ounces


  • The tester has an LCD display for accurate voltage readings
  • It has a needle-sharp stainless-steel pointer for easy piercing
  • The tester has a long cable length of 11 ft for convenience
  • It is multi-functional and can be used from 3-48V systems
  • It is small and ergonomic for easy access to confined spaces


  • It does not have a lamp in it that will light up when you have voltage; you will be forced to check the LCD

5. OTC 3633 Mini-Coil Cord Circuit Tester

This is a simple-to-use electric tester that you can use to locate if you have shorts or open circuits on any surface.

It is equipped with a needlepoint stainless steel probe that makes it easy to probe or pierce. The probe features an alligator clip for more convenience. It has a long-coiled cord that is 12 feet long. The tester is ergonomic with a slim clear handle that is easy to use.

The automotive tester can be used for both 6V and 12V systems.

Product Information

  • Product Dimensions: 2.85 x 8.55 x 1.7 inches
  • Product Weight: 0.035 ounces


  • It features a needlepoint stainless steel probe that can pierce any surface.
  • The tester has an alligator clip for convenience in handling it
  • It has a long cord of 12 feet for convenience
  • The tester is ergonomic with a slim clear handle that is easy to use
  • It can be used for 6V and 12V systems


  • The cord is made of coiled plastic that may fall off of things when you are using it.

Buyer’s Guide

Any of the five testers will serve you perfectly for automotive purposes. With five choices, it may be confusing which one to settle on. In this part of the guide, we focus on the details that set them apart to help you decide.

Tester with LCD Display

Most testers normally have an inbuilt light that flashes whenever voltage is detected. However, if you need a more specific tester, then going for a tester with an LCD screen will be ideal. In this case, the TOPEMAI 3-48V Digital LCD Display Circuit Tester would be the best choice for you as it has an LCD display.

Tester with the Longest Cord

A long cord is convenient in many ways. In this case, the tester with the longest cord is the OTC 3633 Mini-Coil Cord Circuit Tester with a length of 12 feet.

Tester for a Wide Range of Circuits

Most testers can test up to 24V. The TOPEMAI 3-48V Digital LCD Display Circuit Tester can test from 3-48V, a reasonable range that will not limit you.

A Tester That Comes in Multiples

If you are looking to buy a tester that comes in multiples, then the SourceTon Professional Circuit Tester comes as a set of two in a pack.

The Most Affordable Tester

When I compare the prices, the least expensive tester in the batch is the EFORCAR Circuit Tester which retails at less than $10.

Our Overall Recommendation 

Our overall recommendation for the best automotive test lights is to go for the EFORCAR Circuit Tester if you are limited budget-wise. Otherwise, our best judgment is the TOPEMAI 3-48V Digital LCD Display Circuit Tester that can do 3-48V and has a digital LCD display for convenience.

Factors to Consider When Looking for Automotive Test Lights

Though automotive test lights may look the same, their features and quality can range quite widely. When searching for the best automotive test lights, there are some features that you’ll want to take into consideration. These include:

Bulb Vs. LCD

There are two main types of test lights; those that use a bulb and those that use LCD. The common old-style versions used to use bulbs, but currently, modern ones use LCD.

The bulb versions are normally cheaper since they just use an incandescent bulb light to indicate. The bulb can be replaced anytime when it is burned out or dead.

As for the LED light indicator, you read the readings of the voltage on the LCD display. It is also a safe-rated computer, and you can charge it using your computer. It is pricier since it is more advanced.

The Cord

Cords are normally made of different materials and are of different lengths. Longer cords are normally more convenient though they should not be too long, or it may be a safety hazard. A long cord also consumes a lot of storage space.

As for the material, some materials are more durable and resilient. Some are safer. You need to ensure the material used is right.

Voltage Range

As much as it is very important first to know the voltage system of the car you intend to test, you also need to know the tester’s voltage that you intend to use. There should be a match.

Most modern cars have a voltage of 12V going up, while old school cars mostly have a voltage of 6-12V. If your car uses a 24V system, then a 12V test light will not work well for you.

It is always better to look for a tester to do the widest voltage range possible for more convenience.

Clip Size

Test lights have different clip sizes. You need to check on the size and also the type of clip. It should be non-slip, easy to open, and an adequate size.

Computer Safe

Most bulb test lights are not computer safe. This is primarily because they use an incandescent bulb that draws out current and can pose a hazard to the computer circuit.

There are, however, some test lights that are computer safe; hence you can be confident that your car’s computer will not be harmed as they do not draw much current from the circuit.

Most of the testers that are computer safe use other power sources such as batteries. Most of these kinds of testers use LED indicators, even though some may look like the bulb type.

LED Indicator

Different light indicators are used; it can either be the Incandescent bulb, LED, or the positive and negative polarity type. As for the LED type, it uses one LED and one transistor. The negative and positive polarity type uses the red and green LED with the circuit board.

The testers that use LED are the safest as they draw less current from the car circuit. It will also notify you easily on the state of current, whether it is present or absent.

Relief Spring

According to many, this is one of the undermined considerations, yet it will help your cord last longer. It will help the cord spring back to its former position so that the cord does not bend for a long time or break.

How To Use a Test Light

As mentioned before, a test light is a vital tool for checking the circuit of your car. You can be able to tell whether there is an electric flow or not. It can help in ruling out many problems than a multimeter would.

Once you identify a good fuse with a test light, you can still check its route to know what may be the problem. A test light can either test for positive voltage or ground.

Testing for positive voltage

As for a circuit, there is a positive power source, i.e., the battery and the ground, which is in the form of exposed metal. 

To test for positive voltage, you attach one end of the tester to the ground and another to the positive power source. If it lights up, then everything is okay; if not, then there is something else to be done that will have to be diagnosed.

Before using your test light, it is advisable that you also test it, and you can do that on the car’s battery. It does not matter what end you use on what; that will not alter the results. So long as one is on the positive power and the other on the ground.

The best part about testers is that most of them have a sharp end that can pierce any surface.

Testing a Ground Circuit

In the same way, an automotive tester can be used for checking the voltage, it can also be used to check a ground circuit. If you are sure of the voltage, but there is still a problem, it may be an indicator to check the grounding point.

To test the ground circuit, attach one end to the positive power source and the other end to the ground wire. If it lights up, it means that the ground is good, and if it does not light up, you should check deeper to diagnose the problem. 

When you are attaching it to the ground, you should look for a point free from paint, rust, plating, or insulation, as that will alter the results. If you test for the ground often, it may be better to invest in an engine ground strap.

Checking a Fuel Injector

Automotive test lights can also be used to check if the fuel injector works. All you have to do is place the clamp to the negative battery terminal and then use the probing end to test the injector circuit. If it lights up, it means the fuel injector works perfectly.

When you are doing any test using a test light, you need to have a wiring schematic. That will help avoid misdiagnosis as sometimes the tester may light up, yet there is no power at a particular source. With a wiring schematic, you can identify the sources of the problem using elimination.


Automotive test lights are one of the vital garage accessories that you should have. Its convenience will save you unnecessary trips to the mechanic as you can diagnose and fix when needed.

All you need to do is to know about the different test lights and their specifications to choose accordingly. Research and comparison help a big deal when you are shopping around.

Reviews can also shape your expectations on what to expect with a certain test light before making the buying decision.