Congratulations to David Culp, of Robinson, Texas! He's the latest winner of our "ASE Question of the Month" random prize drawing.

Our December issue features diagnostic tales and tribulations. So we tested your fundamental electrical troubleshooting skills!

Technician A says that verifying power to a component is best done with a test light, inserting it into the end of the component's unplugged connector on the harness side. Technician B says that the best way to verify power is to perform a voltage drop test on the power side of the circuit with the component plugged in and turned on. Who is correct?

A.  Technician A

B.  Technician B

C.  Both A and B

D.  Neither A nor B

Did you answer B?

Only Technician B is correct. Using the method Technician A describes would only measure Open Circuit Voltage. Without current flow, there is no voltage drop and any extra resistance in the power side of the circuit would remain undetected.

Had you tried the question, you could have done like David did, and entered our random drawing for a collectible diecast, provided and sponsored by Federated Auto Parts! If you didn't, it's not too late! Click HERE to take our January test.

About the Author

Pete Meier | Creative Director, Technical | Vehicle Repair Group

Pete Meier is the former creative director, technical, for the Vehicle Repair Group with Endeavor Business Media. He is an ASE certified Master Technician with over 35 years of practical experience as a technician and educator, covering a wide variety of makes and models. He began writing for Motor Age as a contributor in 2006 and joined the magazine full-time as technical editor in 2010. Pete grew the Motor Age YouTube channel to more than 100,000 subscribers by delivering essential training videos for technicians at all levels. 

Connect with Pete on LinkedIn.

Sponsored Recommendations

Learn how electronic parking brake actuators have replaced manual systems and now play a key role in advanced safety features like automatic emergency braking. This WIYB Training...
Not all fuel injectors are created equal. In this WIYB Training Series, we compare Standard® Fuel Injectors against OE, low-cost imports. See why precision engineering and rigorous...
Carrying active OEM subscriptions for all manufacturers is not possible for many shops. However, access to this software is required for certain modern vehicles and repairs, and...
Learn how to properly lubricate your AIRCAT air tools to keep them running at peak performance. Discover essential daily maintenance and storage techniques, along with the right...

Voice Your Opinion!

To join the conversation, and become an exclusive member of Vehicle Service Pros, create an account today!