Thanks to our Partners, Pico Technology, and Autel
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Powered circuit testers tend to produce strong opinions. Some specialists consider them indispensable time-savers. Others see them as dangerous tools that make it far too easy to damage a circuit.
In this episode, Matt examines where tools such as the Power Probe, Autel powered circuit tester, and metered test lights fit into an automotive diagnostic process. The ability to apply power or ground can be dangerous without an understanding of the circuit, but the same can be said of jumper wires, scan tools, oscilloscopes, and nearly every other useful diagnostic tool.
Matt also opens the episode with thoughts on the unexpectedly short Conor McGregor and Max Holloway fight. Rather than focusing only on the disappointing result, he considers the discipline and preparation required to attempt something difficult, even when the attempt ultimately fails. That leads to a broader shop question: How should a leader respond when a capable employee puts in the work, takes on a difficult task, and still comes up short?
In This Episode
- The difference between a powered circuit tester and a metered test light
- Why Power Probe-style tools remain controversial
- The risks of applying power or ground to an unknown circuit
- Why Matt prefers the speed and simplicity of the Power Probe III
- Using powered testers on motors, relays, power windows, and power seats
- Testing fuel-pump power and ground circuits
- Using the tester’s circuit breaker to evaluate whether a circuit can carry current
- Why unloaded voltage readings can be misleading
- The value of placing a known load on a circuit
- Why corrosion can pass a voltage test but fail under load
- Matt’s experience with the Lisle and TOPDON metered test lights
- Why an incandescent test light is often more useful than an LED test light
- The difference between a dangerous tool and an improperly used tool
Key Takeaways
A voltage reading does not necessarily prove that a circuit can perform useful work. A connection may show battery voltage through a meter and still fail when current is required.
A metered test light can combine the speed of a traditional test light with an actual voltage reading and a known electrical load. Matt regularly uses this type of tester when checking fuses and evaluating circuit integrity.
A powered circuit tester can also shorten the process of separating a failed component from a power-feed or ground problem. Matt describes using one at a fuel pump to verify the power side, ground side, and pump operation without repeatedly changing tools or building several different jumper-wire arrangements.
The tool does make applying power or ground unusually easy. That convenience is precisely why the user needs to understand the circuit before pressing the switch.
The Larger Question
Should a tool be dismissed because it can cause damage in the wrong hands?
A powered circuit tester can damage a circuit. A jumper wire can do the same. A scan tool can lead to expensive parts replacement when its information is misunderstood. The potential for misuse does not necessarily make the tool inappropriate. It may mean the specialist needs more knowledge before using it.
Listener Question
Do powered circuit testers belong in a professional diagnostic arsenal?
Are they valuable time-savers, unnecessary risks, or a little of both? What version do you use, and where has it proven most useful?
Mentioned in This Episode
- Power Probe III
- Power Probe Hook
- Autel powered circuit tester
- Lisle metered test light
- TOPDON TC001/CT100-style circuit tester
- Incandescent and LED test lights
- Fuel-pump circuit testing
- Relay and electric-motor testing
Thanks to our Partner, Pico Technology
Are you chasing elusive automotive problems? Pico Technology empowers you to see what's really happening. Their PicoScope oscilloscopes transform your diagnostic capabilities. Visit PicoAuto.com
Thanks to our Partner, Autel
From drivability diagnostics and TPMS service to ADAS and advanced safety systems, Autel helps technicians follow OEM procedures and repair with confidence. Learn more at Autel.com
Contact Information
The Automotive Repair Podcast Network: https://automotiverepairpodcastnetwork.com/
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