Best digital multimeters
Which of these multimeters makes electrical fault finding the easiest?
Electrical problems are both common and difficult to diagnose. Poor earths, broken wires and dodgy batteries can all cause havoc and take hours to trace, even on fairly simple cars.
This makes a good multimeter an essential piece of equipment in any DIY mechanic’s tool kit. Even the most basic testers will sense voltage so you can check if a wire is getting power, and continuity so you can test if a circuit is complete, or an earth ground is sound.
A resistance gauge is also useful for checking proportional switches, such as those for heater controls.
How we tested
We were looking for multimeters that make life easier for a DIY car fixer. Automatic sensors were preferred because of their simplicity, but we also liked a manual back-up selector for situations where you might want a different measurement.
Backlighting makes for effortless meter reading in dark footwells and engine bays, while longer cables and props mean you won’t struggle to hold it in tight places. Cable storage or a case helps keep your toolbox tidy too. Finally, we took price into account.
Verdict
When it comes down to the wire, it’s the TESMEN multimeter we will be reaching for. Its compact size, useful features and easy-to-use tech make it unbeatable, and the price is the icing on the cake.
Used - available now
2018 Porsche
Cayenne
70,000 milesAutomaticPetrol4.8L
Cash £27,995
2026 Mercedes
AMG GLE 53
34,700 milesAutomaticPetrol3.0L
Cash £62,000
2019 Suzuki
SX4 S-Cross
31,108 milesManualPetrol1.4L
Cash £11,900
2018 Audi
A3 Sportback
63,149 milesAutomaticPetrol1.5L
Cash £14,302The LAP AC/DC Digital Multimeter is similarly smart and tough. For more professional users, the Draper DMM404 has all you need – at a price.
Best digital multimeters
TESMEN TM-510 Digital Multimeter
- Price: around £17
- Rating: 5 stars
- Contact: amazon.co.uk
It’s not just the low price that makes the TESMEN a winner here. The compact unit is encased in a tough plastic shell, and is brilliantly easy to use in automotive environments, with no dial to play with. It relies on buttons and a backlit display that is more comprehensive than any rival’s here.
The Smart Auto Mode instantly switched between our measurement tasks, without the need for manual inputs, while overall practicality is boosted with the inclusion of a torch function and a fabric storage case.
LAP AC/DC Digital Multimeter
- Price: around £33
- Rating: 4.5 stars
- Contact: screwfix.com
The LAP is delightfully simple and easy to use, thanks to a Smart mode that automatically selects the appropriate function as soon as you apply the probes to points you want to test. There’s also the option to manually select the measurement you need via a dial.
We loved the tough cushioned case, the large stand to hold it steady on the workbench, and slots to store the cable’s probes. However, it doesn’t look to be particularly great value compared with the winning TESMEN unit.
Draper DMM404 Auto & Manual Ranging Digital Multimeter
- Price: around £50
- Rating: 4 stars
- Contact: drapertools.com
The larger of the two Drapers in this test has the highest price, which means it might only appeal to regular users.
Still, you get your money’s worth, with plenty of features that will appeal to both automotive and domestic DIY enthusiasts. The big display is backlit and clear to read, showing results for voltage, current, resistance, diode and continuity testing.
It also has a stand and storage for the cable probes, although they don’t fit very well. Thankfully, there’s a case to keep them tidy.
TIS 258 Digital Multimeter
- Price: around £20
- Rating: 3.5 stars
- Contact: toolstation.com
There’s nothing much wrong with the TIS 258, especially with it being well priced compared with most rivals in this test. It has a separate temperature probe, backlight, stand, and storage clips for the probes. The cables are an impressive 88cm long too, second only to the Draper DMM404.
However, it feels old fashioned to use, with manual selections via a dial. It irritatingly defaults to AC measurements as well.
Draper DMM300 Automotive Multimeter
- Price: around £28
- Rating: 2.5 stars
- Contact: drapertools.com
The DMM300 looks like it could be a winner on paper because it has automotive-specific functions, such as the ability to read engine revs. Unfortunately, the clamp needed to measure this is a £35 extra.
Judged purely as a multimeter, the Draper scores with a case, stand and backlight, but there’s little else to make us recommend it – especially at the price.
Sealey MM20 8-Function Digital Multimeter
- Price: around £24
- Rating: 2.5 stars
- Contact: sealey.co.uk
On the plus side, the MM20 is comfortable to hold, and the tough case feels as though it is designed to survive life in a garage. There’s a separate lead to measure temperature too.
But it relies entirely on manual selection of functions, the display is small, and there is no backlight or probe storage. Also, the continuity test’s buzzer is barely audible, and the unit has the shortest cables in this test.
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