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Cordless Circuit Tester

Cordless Circuit Tester

Item # PTW2979
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Lowest Prices for the best wiring from Performance Tool. Cordless Circuit Tester part number PTW2979 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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Performance Tool Wiring - PTW2979

  • Tools for Wiring
  • Testers
  • Circuit Tester
  • Performance Tool


  • Performance Tool cordless circuit tester detects voltage from 3v to 28v
  • Ground wire or clip is not required
  • Safe with ECMs, sensors, transducers, and the like
  • 2 Type "N" long-life batteries included
  • Buzzes and lights up if power is detected when the tester is grounded
  • Overall length: 6"

W2979 Cordless Circuit Tester




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Video of Cordless Circuit Tester

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Performance Tool Cordless Circuit Tester Review

Today we'll be taking a look at the Performance Tools Cordless Circuit Tester, part number PTW2979. Now this is going to be your Performance Tool Circuit Tester. It's going to be a handy little thing that's only about 6 inches long. It detects voltage from 3 volts all the way up to 28 volts. The nice thing about this is it's going to be cordless. It's going to use you as the ground so you're not going to need a wire or a clip with it.

It's going to be safe to use on ECMs, sensors, and transducers as well. It comes with 2 end type long term, long life batteries. Now here we'll go ahead and test it out. It does come with your probe as well, so if you like to just press that on to your wires and then probe your wires you can. If you have a four-pole like we do here, you can just remove that cover, hold it on the chrome or shiny part here. Then you're just going to touch the ground.

This is going to use you as a ground, so if we don't touch the ground, we're not going to get anything out of it. If we touch the ground with our finger with our freehand, you'll hear the audible beep as well as see the light flash. Now, if we let off that ground . So you'll know right away if you have a bad ground. That will do it for our review of the Performance Tools Cordless Circuit Tester, part number PTW2979..


Customer Reviews

Cordless Circuit Tester - PTW2979

Average Customer Rating:  5.0 out of 5 stars   (2 Customer Reviews)


- PTW2979
by:

Still using it on occasion. Have to watch the batteries. 315493



- PTW2979
by:

Great products and great people to deal with. 266699


2
2

Ask the Experts about this Performance Tool Wiring

  • Finding the Stop Light Switch Wire on a 2014 Volvo S60
    Typically the location of the stop light switch is up and behind the brake pedal but you would need to use a circuit tester like part # PTW2979 to verify which one it is. The wire you are looking for will show power only when the brake pedal is pressed. If you check out the installation video (23:40 mark) that I attached you can see this testing being done on a 2012 Volvo XC90. If you don't already have a brake controller then I recommend the Tekonsha Prodigy P3 # 90195. This is...
    view full answer...
  • Troubleshooting Intermittent LED Tail Lights
    The problem you are experiencing with intermittent LED tail light functionality is very likely because you have a poor ground, which can cause all sorts of funky problems. What you should do is make absolutely sure your grounds are attached to bare metal surfaces and free of any paint, dirt or corrosion. If you have a good ground you will want to move on to your connectors and check them for corrosion, which can be green or white in color. A build-up of corrosion can interfere with...
    view full answer...
  • Troubleshooting Tips for No Lights on Trailer
    So there's a number of potential reasons why your trailer lights may not be working, and I'll go over the troubleshooting steps you'll need to take in order to try and find the problem. The first thing to do is take a look at your owner's manual to locate any trailer fuses or relays and ensure they are all there and in working order. If they are, in order to determine the specific problem you will need to purchase a circuit tester if you do not have one - the very handy Cordless Circuit...
    view full answer...
  • Trailer Lights Work But Brakes are Not Working
    If you have a 7-Way on both your trailer and tow vehicle you will first want to make sure that you have a brake controller, like the Tekonsha Prodigy P3 # 90195. A brake controller is what is used to send power from the tow vehicle and tells the trailer how much braking power is needed. If you do not have one, just let me know what the year/make/model is of your tow vehicle and I will be happy to help you make sure you have the correct equipment. If you do already have a brake controller...
    view full answer...
  • Can Performance Tool Wiring # PTW2979 be Used on More than Trailer Applications
    The Cordless Circuit Tester # PTW2979 is not limited to only trailer circuit testing. You can use it in basically any application that has voltage between 3 volt to 28 volt. I attached a review video for this for you to check out as well.
    view full answer...
  • Troubleshooting Trailer Lights That Won't Come On
    There are a plethora of potential issues so there are a number of troubleshooting steps I can offer. The first thing to do is take a look at your owner's manual to locate any trailer fuses or relays and ensure they are all there and in working order. If they are, in order to determine the specific problem you will need to purchase a circuit tester if you do not have one - the very handy Cordless Circuit Tester # PTW2979 would be my strong recommendation due to how easy it is to use - and...
    view full answer...
  • Troubleshooting Electric Brakes Not Working
    Although I'm not quite sure what you are referencing when you say your ground is not working there is a way you can find out if the issue is on the brake controller, truck, or trailer. To test the brake controller, sever the blue wire a couple inches from the back of your controller. Then use a circuit tester such as # PTW2979 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override; if it shows power at idle then there...
    view full answer...
  • How to Determine Correct Wires for Trailer Light Wiring on a 2014 Land Rover LR4
    The typical layout of wiring is as follows: Green - Right Turn/Stop Yellow - Left Turn/Stop White - Ground Brown - Tail/Running Blue - Brake Controller Output Red or Black - 12V Power Purple - Reverse Since each vehicle is different and manufacturers haven't decided on a universal system it is better for you to verify the different wire functions with a circuit tester like part # PTW2979. I am attaching some pictures to demonstrate where each function is connected to for both...
    view full answer...
  • Troubleshooting Trailer Back-Up Lights not Working
    It could be a fuse that is causing this issue, and that's actually the first thing I recommend checking; you will need to take a look at your owner's manual to locate any trailer fuses or relays and ensure they are all there and in working order. If they are, in order to determine the specific problem you will need to purchase a circuit tester if you do not have one - the very handy Cordless Circuit Tester # PTW2979 would be my strong recommendation due to how easy it is to use - and test...
    view full answer...
  • Troubleshooting Peterson Lexan 410-25 Running Tail Lamps Not Working
    Trailer tail lights usually have 2 different circuits routed to them; stop/turn and then the running (tail) lights. Since your turn light functions are working but the tail lights aren't that just means you need to troubleshoot that specific circuit. Problems with a lighting circuit can be located on the tow vehicle or the trailer so you can determine which end to troubleshoot by testing the running (tail) light circuit on your vehicle trailer wiring connector with a circuit tester like...
    view full answer...
  • How to Determine Wire Functions of Vehicle 7-Way
    To determine how to wire any connector you will need to determine the function of each wire with a circuit tester as there is no universal color code. I recommend the very handy Cordless Circuit Tester # PTW2979 due to how easy it is to use. Once you find their functions you can match them to your 7-way, and the accompanying diagram shows the connections for the different style of 7-ways. I have added a link to a help article on trailer wiring I very strongly recommend reading.
    view full answer...
  • Troubleshooting Trailer Lights Which are Not Working
    If your rear indicators are not working, it's almost certainly a poor ground, so the first thing to do is take a look at your ground connections to make sure they are attached to bare metal surfaces and free of any paint, dirt or corrosion. What is probably happening is the ground isn't strong enough for the load put on it and fixing this can resolve the issue. After that, refer to your owner's manual to locate any fuses or relays and ensure they are all there and in working order....
    view full answer...
  • Trailer Blinker and Turn Signals Only Work on One Side
    Since it sounds like you were trying to match up colors during your install I believe you are correct that you wired it incorrectly. Although there are common wiring colors, there are no rules saying that everything has to be wired using any specific colors. This goes for both vehicle and trailer side. If you connect wire colors instead of checking their functions you could end up with an incorrect wiring system. What I recommend doing is using a Circuit Tester # PTW2979 to test the...
    view full answer...
  • Troubleshooting Trailer Lights not Working Properly
    The first thing to do is take a look at your owner's manual to locate any trailer fuses or relays and ensure they are all there and in working order. If they are, in order to determine the specific problem you will need to purchase a circuit tester if you do not have one - the very handy Cordless Circuit Tester # PTW2979 would be my strong recommendation due to how easy it is to use - and test the connector on your vehicle after disconnecting it from your trailer. Check the wiring going...
    view full answer...
  • Brake Controller Not Getting Signal From Stop Light Switch on 2015 Ram 2500
    If you have tested the red wire (the stop light switch wire) from the harness with a Circuit Tester like # PTW2979 and that wire does not have a signal, the wire on the harness has somehow been damaged. That would be the only reason there wouldn't be a signal since you mentioned checking the fuses and the connections and your brake lights working. If this is the factory controller, I strongly recommend upgrading to an aftermarket brake controller, which are absolutely a higher quality...
    view full answer...
  • Troubleshooting Brake Controller not Working on 2006 GMC Sierra
    There are a number of troubleshooting steps you can undertake in order to try and determine what the issue is with the brake controller on your 2006 GMC Sierra To test the brake controller itself, sever the blue wire a couple inches from the back of your controller. Then use a circuit tester such as # PTW2979 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override; if it shows power at idle then there is an issue with...
    view full answer...
  • Troubleshooting No Running Lights on Trailer
    There are a few common causes to just one function on the trailer not working such as the running lights in your case. A good place to start any troubleshooting process like this one is to test the connector on your tow vehicle with a circuit tester like # PTW2979. Test the running lights pin on the connector with this function activated on the vehicle. If you get power at the pin then you know the issue is on the trailer. If you don't get any power there then the issue is actually...
    view full answer...
  • E1 Error Code on Hopkins Reliance Brake Controller
    The E1 error code on the 47284 brake controller - which is the Hopkins Reliance - indicates a trailer not connected. So getting this error when you are hooked up means there is an issue either with your trailer connectors or possibly a short on the blue brake wire. Many times that can be attributed to one of your connectors having corrosion or possibly some type of debris interfering with the signal so start by taking a look at your connectors and clean the corrosion if necessary. This...
    view full answer...
  • Troubleshooting No Trailer Lights and Blinkers on Tow Vehicle Side
    Good job narrowing down the issue to your tow vehicle! If you have tried swapping out fuses you know work with the fuses that carry the stop/turn signals for your trailer then the next step is to figure out what is happening to the power. You need to start at the connector at the rear of your vehicle and using a circuit tester like part # PTW2979 you need to pierce the wiring at different locations to see where the signal stops. While you are doing this you need to look for places where...
    view full answer...
  • Troubleshooting No Brakes for OEM Brake Controller on 2014 Ram Pickup
    If the F11 fuse in your 2014 Ram pickup is in good shape then the next thing to check is the brake controller output on your 7-Way socket. Using a circuit tester like part # PTW2979, test the pin in the 5 o'clock position while using the manual override with your brake controller set to the highest power output setting. If you are getting power on this pin then your truck is fine and you need to inspect the brake wiring on your trailer. If you aren't getting power on this pin then either...
    view full answer...
  • Troubleshooting Camper Brakes Locking Up With 2014 Nissan Xterra
    From what you are describing, with the brakes locking up when you are trying to pull away with your 2014 Nissan Xterra, it sounds like the brake controller is wired incorrectly as opposed to an issue with Harness # 118266. It may be that the red wire from your controller is not wired to the cold side of the stop light switch. Use Circuit Tester # PTW2979 and find the wire that has power only when the brake pedal is pressed and connect it to the aforementioned red wire. Should that...
    view full answer...
  • Troubleshooting No 12V Power at 7-Way on 2014 Ram Truck
    If you aren't getting any power at the 12V pin on the 7-Way connector (which should be at the 1 o'clock position) for your 2014 Ram then a missing or blown fuse is the most likely cause. I took a look at the online owner's manual for your truck and it looks like there should be a 30 amp fuse located in the F30 position inside the power distribution box (under the hood near the battery). Check to make sure this fuse is present and in good condition. If this doesn't resolve your issue...
    view full answer...
  • Troubleshooting Lights on Trailer not Working
    There are dozens of reasons why the lights on your trailer don't work so I will give you a number of troubleshooting steps you have to take in order to potentially determine the issue. Additionally, please note that on most vehicles the tow package wiring is independent of the vehicle lights which is why everything on your truck works. You will need to use a circuit tester such as # PTW2979 to test the connector on your Silverado after disconnecting it from your trailer. Check the wiring...
    view full answer...
  • Only Running Lights Are Working on Trailer
    Since only the running lights are working on your trailer, the first thing to do is take a look at your owner's manual to locate any trailer fuses or relays and ensure they are all there and in working order. If they are, in order to determine the specific problem you will need to purchase a circuit tester if you do not have one - the very handy Cordless Circuit Tester # PTW2979 would be my strong recommendation due to how easy it is to use - and test the connector on your vehicle after...
    view full answer...
  • Troubleshooting No Trailer Turn or Brake Lights with 2015 Ford F-250
    There are a number of possible reasons as to why the trailer turn and brake signals aren't working with your 2015 Ford F-250, and depending on how you're currently testing the lights the issue could either be on the truck or trailer side. To start I recommend using a circuit tester like # PTW2979 to test the 7-Way on your F-250. Test the brake/turn signal pins on the connector while you have a buddy flip on those functions in the cab. If you get power on the tester you know the problem...
    view full answer...
  • Troubleshooting Trailer Lights When Connected to 2005 Jeep Grand Cherokee Limited
    The best way to troubleshoot trailer lights not wiring is to test each half of your towing rig separately. So for your 2005 Jeep Grand Cherokee you'll want to use a circuit tester like part # PTW2979 to ensure that each of the pins are sending power back to the various functions. Since it sounds like you already tested this your next step is to test the wiring on your trailer. You can test the trailer wiring by either plugging it up to another vehicle or by taking a 12V battery, grounding...
    view full answer...
  • Troubleshooting Right Blinker on Vehicle Causing Left Blinker on Trailer to Function
    There are a few possible reasons as to why the right turn signal on your tow vehicle is causing the left tail light on your trailer to blink but most likely there's a simple crossing of wires on the trailer or a short on the vehicle. What I first recommend doing is taking a circuit tester like # PTW2979 to test the pins on your vehicle side connector. Test the pin for the right turn/brake signal on the connector while you have that function activated on the vehicle. If you don't get...
    view full answer...

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Info for this part was:

Expert Research:
Jameson C
Video Edited:
Jacob T
Video by:
Dustin K
Updated by:
Sarah W
Updated by:
Erin H
Installed by:
Jared G
Written by:
Jacob W

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