Circuit Tester Test

A circuit tester will help you get to the root of electrical glitches. We try seven

Auto Express Car Reviews

April 2008

Despite the complex electronics of today’s cars, many glitches can still be solved by a simple test lamp.

While most DIY mechanics will shy away from tackling problems involving sensors and the like, many will take on a dodgy light, or kit such as heaters, wipers or switches. And for a quick, easy way of tracking down these faults or a blown fuse, look no further than a test lamp.

Basic circuit testers are little more than a screwdriver with a lead and bulb in the handle, and are often considered to be a poor man’s multimeter, but recent units are more advanced in their design.

Many can show the voltage and polarity at the probe point – much more useful than just knowing whether a feed is live or not. They can also power up suspect components – such as bulbs or motors – simply by placing the probe on the terminal, connecting the earth lead to the casing and pressing a button.

Proving whether components work or not often makes it much easier to trace electrical gremlins. So which circuit tester is best? We tried seven to find out.

The Test

We wanted a wide range of skills from each piece of kit, and they needed to be easy to use. Voltage and polarity indicators were plus points, as was the ability to energise components.

After testing each tool, we rated them for practicality, looking for a sharp point to pierce cable insulation (above) and a useful earth lead length. As ever, value for money was balanced against features and performance.

Verdict

Gunson’s 77038 is a clever product which delivers many basic – and very sophisticated – multimeter functions in an easy-to-use probe tool. It took our Best Buy, although the fact it can’t energise components is disappointing.

The Draper 57680 and Gunson’s G4166 are virtually identical. Both are basic, yet much more practical than simple, screwdriver-style testers. However, the Draper’s cheaper price earned it our Recommended award.