Skip the auto shop - Our mechanics make house calls

The Best Tool For Mechanics to Diagnose Electrical Issues

The Best Tool For Mechanics to Diagnose Electrical Issues Mac Tools probe electrical tester
Image: Mac Tools

Most mechanics agree that one of the most frustrating problems to diagnose is electrical gremlins that always seem to pop up at the worst time for car owners. Although today's modern cars, trucks, and SUVs are assembled with highly complex electrical systems, they still work under the basic principles that older vehicles used to power systems. Due to this fact, most ASE certified mechanics still use the basic probe electrical tester to diagnose most electrical issues found on modern and older vehicles.

What is a power probe electrical tester?

A power probe is a brand name for an electrical tester that was developed many years ago and designed for mechanics to measure the true RMS value of alternating current. Today, there are multiple manufacturers and tool companies that sell electrical current probes that are designed to check three primary electrical signals:

  • Identifies a positive circuit
  • Identifies a negative circuit
  • Identifies an open circuit

One of the most common circuit failures on cars, trucks, or SUVs is a faulty ground or a blown fuse. The power probe electrical tester has an easy to use power test feature that can detect whether the circuit has a resistive or bad ground, or if it's a complete circuit. This allows the mechanic to trace and identify the problem circuit and eliminate good circuits which expedites the diagnostic process and discovers the true source of the electrical problem much easier.

What electrical problems can you diagnose with a power probe?

A power probe electrical tester is designed to connect to the vehicle's battery and often has a 20 foot or longer cable that allows a mechanic to use it from bumper to bumper. By connecting to the positive and negative terminals, mechanics don't have to spend additional time looking for good ground connections, which can lead to false continuity readings in standard electrical probes.

In general, there are five individual components that contribute to electrical issues:

  • Diodes
  • Switches
  • Relays
  • Fuses
  • Wires

There is a green LED light that tells a mechanic that the circuit is open (meaning there is a problem that needs to be fixed) or that it has continuity (meaning the circuit is good). This device also has an auxiliary ground lead that allows mechanics to activate electrical switches and test them instantly. Most mechanics use a power probe to complete multiple electronic inspections including:

  • Activating electrical systems that have positive and negative source voltage
  • Testing sensor
  • Tracing electrical signals and capturing glitches in the electrical system of a vehicle
  • Electronic fuel injector testing
  • Testing trailer lights, brakes and turn signals
  • Complete electrical resistance testing

A power probe electrical tester is extremely portable, allowing mechanics on the road to simplify the process of diagnosing and repairing electrical issues when time is limited and their customers need to get their vehicles back on the road. If you’re already a certified mechanic, you enjoy working with customers on the road and you’re interested in working with YourMechanic, submit an online application to work for YourMechanic for an opportunity to become a mobile mechanic.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0523 OBD-II Trouble Code: Engine Oil Pressure Sensor/Switch High Voltage
P0523 trouble code means there is an issue with the engine oil pressure sensor often due to faulty wire connection or wrong engine oil.
How to Replace the Rear Hub Bearing on a Ford Explorer
Wheel bearings allow the car's wheels to give you a smooth ride. A howling or grinding noise is a sign that your hub bearing should be replaced.
P3485 OBD-II Trouble Code: Cylinder 11 Exhaust Valve Control Malfunction
P3485 means an issue with cylinder 11’s exhaust valve control circuit which causes sluggish acceleration and decreased fuel economy.


Related questions

Q: What tool is needed to open the bleeder valve on a 2006 Jeep Wrangler's clutch slave cylinder?

You should have a small Allen type of screw bleeder on the top side of the slave cylinder that needs to be turned loose counter clockwise until the fluid pressure is released and the shaft can be pushed back and...

Q: Advice on working as a mechanic

I'm kind of unique because I learned from my grandfather, who was a mechanic at the corner of Texaco gas station in New York when I was a kid. So I learned hands-on from my grandfather. He wouldn't teach me...

Q: Need to change a CV joint

There are quite a few special tools required. Although all of the tools are important, of high priority you will need a high capacity, properly calibrated torque wrench because the CV axle nut is torqued to 188 ft-lbs. For ease,...