Education/Info Tool Review

Before You Buy a Power Probe Look at Autel’s PS100

Probe testers are a tool you can’t live without and Autel’s PS100 is Top of the Line. 


I know, you have a test light. What can you do with a probe tester that you can’t with a test light? In a world where cars are essentially big computers, it’s more important than ever to have the best electrical diagnostic tools. I’m gonna explain to you in this post how to use a probe tester to improve productivity. Im also going to show you the features of an Autel PS100 probe tester versus a Power Probe IV and even the Snap On EECT900.


Picture Autel ps100 probe tester on Amazon
Click on the photo for more details and the latest deal on the Autel PS100 probe tester by Autel.

I own the Autel PowerScan PS100 probe tester which I use every day for electrical diagnostics. I decided to go with the Autel because it cost around $150(!) less than a Power Probe IV and $250 less than a Snap On EECT900, but had all of the same features. It’s closest comparison is the Power Probe IV due to the fact that both come with a similar hard-shell carrying case which is 100% necessary. You can buy a Power Probe 3 for a little bit more than the PS100, but it’s only going to come with a cable and no carrying case in a cheap plastic packaging. Storing the PP3 will be a challenge due to the long cables and sharp probe.

I ordered my PS100 on Amazon because it was the best price and had it in two days which was the same amount of time it would have taken to order a Power Probe 3 or 4 and much quicker than waiting for Snap On to order me a probe tester off the tool truck.

Autel is a trusted name with pro technicians and even more-so with electrical and OBD diagnostic tools, so it’s not like I bought a Wal-Mart brand generic probe tester. Those generics do exist and a generic probe tester would be better than not owning one at all to be completely honest.


The Autel PS PowerScan 100 sells for as little as $88.  The PS100 comes with a heavy carrying case and a total of twenty feet of cable. A Power Probe 3, the outdated version of the probe tester sells for around $130 and comes in a plastic package, no carrying case and no extra cable.


Autel PowerScan PS100 probe tester
This is an actual photo of my Autel PS100 probe tester electrical diagnostic tool. As you can see, it has a sleek design compared to the Power Probe.


Autel’s diagnostic scan tools are rated among the best. Autel even ranks above Snap On by many technicians. The one I linked to is a $35 home use scanner, but Autel makes some of the best scan tools on the market. That’s a post for another time- and trust me I’m working on a good Zeus versus MaxiSys comparison that I’ll link to when I finish.


This is the Power Probe 3 with a case that costs is 40% more expensive versus the PS100.


Another good option that is cheaper than Power Probe and Snap-On is the TopDiag probe tester.

TopDiag P200 Diagnostic Probe Tester

The point I’m making is whether it’s an Autel or Power Probe, it’s going to be critical to your electrical diagnostics to own at least some version of a probe tester. I’m going to explain what you can do with a Power Probe, Autel PS100 or other probe style electrical tester and why they are worth every penny they cost.


Related Post- Snap-On Won’t Tell You About This Neck Light

How Snap On’s  EECT900 Compares to the Power Probe IV and Autel PS100


Snap-On does have a probe tester in their lineup- the EECT900 that they call a multi-probe. How does the Snap-On version compare to Power Probe and Autel when it comes to the best probe testers?

Although the multi-probe EECT900 claims to have more advanced features, Snap-On’s probe tester is made by Power Probe. Nearly identical to the PPH1 “The Hook”, it is hard to imagine that the EECT900 can do anything a Power Probe or Autel can’t. And it sells for over $400 on the tool truck. This is just another scenario where there’s a cheaper alternative to Snap-On.

Tool truck fanboys will tell you that the EECT900 is better than a Power Probe but it’s not- and it’s very awkward to hold. One issue with the Snap-On probe tester that really hurts it is the physical design. I tested my dealers demo-unit a while back and I was not a fan of the design of the EECT900.

Engine bays and electrical systems have become ever-more compact and the EECT900 is big and hard to hold. Using the Autel probe tester is much more comfortable and it’s probe gets in to places the Snap-On version can’t come close to.

If the design of Snap-On’s probe tester is what you desire, check out this TopDiag probe tester eBay for just over $100.

Stay off the truck and buy a Snap-On alternative.

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What can I do with my Autel PS100 or Power Probe Citcuit Tester?


Here I’m going to give you the uses of a probe tester, but I’m also going to give you examples of how to use the Power Probe or PS100 and their functions. Autel’s PS100 and the Power Probe IV do almost the exact same thing. So when I explain to you what one does, you can safely assume the other does the same or something very similar.


Autels PS100 PowerScan can do everything from provide 12 volts to an electrical circuit to grounding out a component to testing for continuity and resistance. Though I still think every toolbox needs a good DMM (multimeter), once you have the PS100 or Power Probe it won’t get used much.


Starting now I’m going to convince you why you need a Probe Tester, what advanced circuit testers like Autel’s PS100 can do and also why you are going to buy one today, not tomorrow. 


Here are the main features of the Autel PS100 


  • AVOmeter (ohms meter)
  • Power and Ground Supply
  • 12-24 Volt Test Light
  • Built-in Flashlight
  • Short Circuit Indicator
  • Continuity Tester
  • Ground Indicator

Main Features of the Power Probe IV 

  • Power and Ground Supply
  • Ohms meter that provides active feedback
  • 12-24 Volt Test Light
  • Bad Ground Indicator
  • Continuity Tester
  • Self-Resetting 8 Amp Circuit Breaker

Main Features of the Snap-On EECT900

  • 12-24 Volt Test Light
  • Built-in Flashlight
  • “Patented” Circuit Breaker Protection when feeding power to components.
  • Built-in Vehicle Battery Status Check
  • Ergonomic (not) hand-hold position
  • Continuity Tester
  • Ground Indicator
  • Ohms meter


As you can see by examining the main functions of each probe tester, all three do the same thing. They use fancy wording to market their circuit tester as better but in real-life use the Snap-On alternatives are just as good or better.


Testing fuses with a Power Probe or PS100 is easy.


I know some of you just said “I can test for a bad fuse with a $10 test light”. And you are not wrong. Checking fuses with a test light is easy and effective. It’s been done by mechanics for decades.


Unfortunately the automotive landscape, especially on the wiring and electrical side is changing at a rapid pace. It’s not just as simple as “does this fuse have power or is it blown?” any longer. Modern power distribution in vehicles has become so complex, a whole generation of mechanics are being forced to retire and the demand for quality, knowledgeable auto techs is at an all-time high.


Certain components like headlights and windshield wipers use a range of voltage from one to twelve volts or less depending on the speed being requested by the driver. The digital display on a probe tester will tell you exactly how many volts you are measuring, not just whether there is voltage or not.


Where the Autel PS100 PowerScan and Power Probe offer more functionality is with some of the “newer”-ish power distribution components. Things like testing the TIPM on a Dodge electrical system are much easier with a probe tester.


Since newer “fuse boxes” are closer to internal circuit boards these days, it’s not always possible to even access the fuse for certain circuits. When Dodge started using the TIPM- or totally integrated power module- testing circuits got a lot harder.


J-Case fuses can be tested with a Power Probe.


How can you check those little square J-Case fuses that have the plastic cover on them? I’m talking about the green, yellow, blue and pink ones.


Photo of a j case fuse


These are called J-Case fuses and they can be tested easily with a Power Probe. All you have to do is attach the alligator clip on the short wire to one side and use the probe to see if the green light comes on. This test shows you that the fuse is connected on both sides.


What does it mean when the green light comes on on the Power Probe or PowerScan? It just means that the ground you attached to one side is completing its circuit to the other side signifying the fuse is good.


Testing relays is easy with a probe tester.


Testing a relay with a PS100 or Power Probe is really easy. Attach the alligator clip supplying ground from the probe to the specified prong and use the tip to give power to the relay. If the relay opens and you hear the click, it’s a good relay. 

There are testers designed specifically for testing relays such as the ones made by Relay Buddy. They are also useful in the tool box of a mechanic for electrical diagnostics but these relay-only testers can run you over $100. Your Autel PS100 is only $88, can test the same relay and will probably already be out of your toolbox, hooked up to the battery and ready to test the relay.


With an Autel Power Scan you can give 12 volts and ground for “bench testing”. 


Giving 12 volts to components can cause expensive issues unless you are familiar with the system. A probe tester in the wrong hands is dangerous until the person learns how to use it properly. There is no manual to tell you what you can give power to with a power probe, it’s one of those things you have to learn with practice and hopefully no burned up modules.

Testing a starter is easy with a probe tester.


An ideal situation to use a probe tester for bench testing would be a blower motor. A component that you just hook ground to one side, power to the other and see if the unit works. Starters are another part that can be bench tested with a probe tester like the PS100. Hooking the power probe up to a ground and then powering up the starter solenoid is usually enough to tell you if the starter is good.


This won’t teach you how to use a probe tester, that takes hands-on use.


This post isn’t meant to teach you how to use a Power Probe or PS100. Only experience and experiments in the field can really teach you. If you read the manual with the electrical tester, you will technically know how to use it. That is, you will know which buttons to press.


Learning how to use the Power Probe to actually diagnose anything electrical is going to be a learning process. One that is well worth it in the end though. If you have knowledge of a vehicle electrical system, it won’t take long to learn how to use the Autel PS100 or Power Probe IV.


I have given you some situations where you might use probe testers in the shop. If you want to know how to use a Power Probe there is a YouTube video. Scanner Danner is also a good resource for diagnostics on YouTube.


Back to giving circuits power with a probe tester for a minute. 


Back to the point of manually giving 12 volts to a circuit. Where could the ability to feed voltage (power) be useful in an automotive diagnostic scenario? Think-


  • Bench testing electrical motors.
  • Testing actuators.
  • Setting up lighting aqoooookkk ok mom I’m such as LED or trailer harnesses.
  • Test relays with the Power Probe.
  • Test the resistance of sensors and other components. (PS100 only unless you buy the Power Probe 4 which is around $226)


Electrical components, sensors and actuators can be tested with a probe tester while still in the car.

Starters and other main electrical components can be tested without ever removing from the vehicle. Before even removing parts, you can energize fuses and relays using a wiring diagram to trace electrical issues to the source.


The probe tester, no matter which one you buy will not diagnose electrical issues for you. These probe testers just give the mechanic a serious advantage when figuring out electrical problems.


Without a wiring diagram and at least some knowledge on vehicle electrical systems you can damage some shit. ECM’s, Body Control Modules and other integral parts of the electrical system are very expensive and easy to fry.


Can a probe tester help you find open circuits?


One of the most common uses for my Autel PS100 is finding open circuits. Having the ability to test a wire at different places in the circuit can help you find the location of an open circuit.


Car wiring harness chewed by rodent causing open circuits.


Just don’t be that guy who pokes through the wire insulation and then leaves it. If you absolutely have to poke through a wire, cover the hole with liquid electrical tape. It costs $8 for a jar and it can be used for many applications in a garage.


Exposed wire corrodes very quickly and ends up green and fuzzy. Eventually it will create an open in the wire. For proof, see the picture above.


Consider this- a high percentage of electrical problems are the result of a prior repair. Be responsible, use the right connecters for the job, cover your connections with heat shrink and just generally use good practices when making electrical repairs and don’t be a hack.

Once you learn how to use a Power Probe, your test light will be a rarity.

I keep saying Power Probe because it’s like “Vice-Grips”. Most people call any locking pliers Vice-Grips because the brand is that well recognized. Power Probe is the Vice-Grip of electrical testers. 

Just like Vice-Grip, other companies like Milwaukee came along and made locking pliers also. Some, like the PS100 by Autel end up being a worthy alternative to the name brands and some like the generic probe testers lack certain functions.. Either way, once you start using a probe tester to diagnose electrical issues you will rarely use a test light.






By John Green

I’m John Green. I’m a 33 year old auto technician from Upstate New York. I have 18 years of experience as an automotive light duty and heavy duty truck mechanic. Cars, trucks and anything with moving parts are my passion in my professional life.

Aside from my life as a technician, I am also a seasoned investor and consider myself very financially literate. I use this other passion combined with my passion for cars, trucks and tools to look for ways to save money for my technician friends.

Raising my three girls and teaching them the proper way of life is my personal passion in life. If you want to know more, just ask! I’m on Twitter, Facebook and YouTube as well!