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Computer Safe Logistic Probe

Computer Safe Logistic Probe

Item # PTW2991
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Lowest Prices for the best wiring from Performance Tool. Computer Safe Logistic Probe part number PTW2991 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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Performance Tool Wiring - PTW2991

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


  • Quickly tests high and low voltages on all vehicle circuits, including computerized engine and body controls
  • Tests power and ground voltages
  • Bright red and green LEDs interpret voltage signals such as ground, power and frequency
  • Computer safe, drawing less than 7 milliamps
  • Works on 6, 12 and 24 volt systems
  • Recoil lead wire able to reach 10 feet
  • Heavy gauge color coded battery clips

W2991 Performance Tool Computer Safe Logistic Probe

W2991 Computer Safe Logistic Probe

Installation Details PTW2991 Installation instructions

California residents: click here

Video of Computer Safe Logistic Probe

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

Video Transcript for Performance Tool Computer Safe Logistic Probe Review

Today we'll be having a look at the performance tools computer safe logistic probe, part number PTW2991. This performance tool logic probe is a cost effective solution in order to check not only power, but ground. Ground is the most important thing in any electrical component. It's the most often overlooked component as well. If you don't have a good ground, no matter what, your electrical component will not work. This allows you to check your ground and your power sources. Here's what a logistic probe looks like.

We have our probe end itself. We have a nice pointed end here where we can reach down inside terminals to check for power or ground. Our LED here changes colors depending on if we're on a power or ground source. We have a 10 foot coiled cord right here. Once we go to our heavy duty battery clutch here, which are color coded.

We've got red for positive and black for ground. This logistic probe will work on 6, 12, and 24 volt systems and only draws seven milliamps of power. We'll start by hooking a red lead up to the positive side of our battery here and our black lead, we'll hook up to our negative side of our battery here. This is our battery cable here, so we'll just go to the other end of it right here. Now, we can test to make sure we have a good ground. We'll go to our ground post right here in our vehicle.

You see, you know you have a good ground when the LED is green. We go over to our positive post of our battery. Now you can see our red LED showing here that we have good power. We can show you how to test fuses with this, too. Probe on one side. You see how we have a red LED, which means we have power on that side of the fuse.

Test the other side. We got red there again, which means our fuse is not blown, and there's constant 12 volt power running through that fuse right now. We know we have a good fuse right there. Now we'll check out the seven and a half amp fuse right above it. You notice that our LED is green. That's because this fuse doesn't have any power running through it right now. This fuse only has power when the ignition is switched on in the vehicle. We'll check out the other side. Again, it's green again, which means that the fuse itself is not blown. It's just there's no power running through the system right now. We know we have a good fuse here. Now, this also doubles as a test light. What that would do is only tell you if you have power going on and now ground. If you want to do that, just disconnect from your positive battery, leaving your ground hooked up. I'll go over here, make sure it's working. Got red for power. Now let's go back to our two fuses that we tested earlier. On our five amp fuse, you can see that yes, we have power on both sides. If we go back to the seven and a half amp fuse, you'll see we don't have anything working anymore. That's because what we're doing is only checking for power. That completes our look at the performance tools computer safe logistic probe, part number PTW2991.

Customer Reviews

Computer Safe Logistic Probe - PTW2991

Average Customer Rating:  5.0 out of 5 stars   (1 Customer Reviews)

- PTW2991

Excellent electrical tester 395826


Ask the Experts about this Performance Tool Wiring

  • Locations for Left and Right Turn/Stop Trailer Fuses on a 2011 Ford F-450 Super Duty
    I took a look in the online version of the owner's manual for your 2011 Ford F-450 Super Duty and it looks like the right turn/stop is fuse location 13 while the left turn/stop is fuse location 14 in your passenger compartment fuse box. In the power distribution box (under the hood) the left turn/stop is location 74 while the right turn/stop is location 75. I recommend verifying this in your copy of the owner's manual. If these fuses look good but you still aren't getting a signal...
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  • Troubleshooting Trailer Disconnected Code for Integrated Brake Controller on a 2017 Ford F-350
    What you need to do is test the 7-Way connector both on your 2017 Ford F-350 and your trailer. Since your F-350 is new I doubt that it is on the vehicle side but you can use a circuit tester like part # PTW2991 and the attached picture of a vehicle 7-Way to make sure that all of the functions are operating properly. To test the 7-Way on your trailer simply take a 12V battery and ground the negative terminal while using the positive terminal to apply power to each pin on the 7-Way. If...
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  • Troubleshooting Running Lights Not Working on Trailer Towed with a 2014 Ford F-150
    The easiest way to check and see if something is not working on your 2014 Ford F-150 connector is to use a circuit tester like part # PTW2991 or a multimeter like part # PTW1714 and test the pin for the running lights (see attached pictures). If you are getting power then the issue is on your trailer side but if you don't get power then you either have a bad fuse/relay or the OEM wiring is damaged. When I checked the online version of the owner's manual for a 2014 F-150 the only fuses I...
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  • Trailer Light Wiring Diagram for 7-Way on a 2019 Chevy Silverado 2500
    According to my research the following wires for the 7-Way on your 2019 Chevy Silverado 2500 should carry the following functions: Green OR White/Green - Reverse White - Ground Blue - Brake Controller Green OR Green/Purple - Right Turn/Stop Red/Black OR Red/Green - 12V Power Brown OR Gray/Brown - Running Lights Yellow OR Yellow/Gray - Left Turn/Stop The reverse light function green wire should be slightly larger than the green wire for the right turn/stop function (if you have...
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  • Relay Locations for Trailer Running Lights on a 2009 Ford F-250
    If you are getting no signal when testing the running light pin on your 2009 Ford F-250, with a tester like part # PTW2991, then it very well could be a fuse or relay. When I looked up the online owner's manual for your F-250 it looks like you want to check the relays in the #42 and #55 positions in your Power Distribution Box. Let me know if this doesn't fix your issue and I can help you troubleshoot further. I have linked some helpful articles on wiring to this answer page for you...
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  • Fuse Location for 7-Way 12V Power Pin on a 2010 Ford F-250
    Check fuse 44 in the fuse block under the hood of your 2010 Ford F-250 as well as the relay in position 56. According to the online version of your owner's manual these are also related to the 12V power pin on your F-250. If those look good then the next thing you can do is use a circuit tester with a probe like part # PTW2991 and check the 12V wire from your 7-Way to your battery. Replace any pieces that are damaged or pinched with 10 Gauge Wire # 10-1-1.
    view full answer...
  • Troubleshooting 7-Way Connector Not Working on a 2000 Chevy Silverado 1500
    If your trailer is working properly with other vehicles then the problem is definitely on your 2000 Chevy Silverado 1500. The fuse that you referenced I believe is for the 12V power but I could be mistaken. I tried looking up the online owner's manual but it didn't really identify the various fuses with numbers. With that being said, the best place to start is right at the 7-Way connector on your Chevy. Using a circuit tester like part # PTW2991 or a multimeter like part # PTW1714 check...
    view full answer...
  • Parts Needed to Install Brake Controller and Wiring on a 2017 Chevy Express 3500 Van
    I will be happy to help you find all of the parts you need to tow your trailer with brakes using your 2017 Chevy Express 3500 Van! To install a fully functional 7-Way connector, and ultimately a brake controller, on your Express Van you will need 4-Way wiring that carries the basic trailer light functions and the Universal Wiring Kit # ETBC7. For the basic light functions I recommend going with the T-One # 118392 which simply plugs in behind your tail lights (see attached installation...
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  • How to Change Out 4-Way at Rear of Motorhome to Work with 7-Way on Trailer
    Thank you for the pictures! What you may be able to do is install the Hopkins # HM47210 on your motorhome to replace your current 4-Way round connector. I'm guessing the 2 wires for your brake controller system are for 12V power and for the brake controller signal. If this is the case then you will need to connect the following functions on your motorhome wiring with the following wires from the Hopkins connector: White - Ground Yellow - Left Stop/Turn Green - Right Stop/Turn Brown...
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  • Finding the Brake Switch Wire to Install a Brake Controller on a 2014 Toyota Highlander
    You have to test the brake switch wires with a circuit tester such as # PTW2991 to determine the correct wire for a brake controller red wire. You want the wire that only has power when the brake pedal is pressed and not with the headlights or turn signals on. On a 2013 Highlander we installed a brake controller on, the brake switch wire was blue. I would start testing with the blue wire on the brake switch if applicable to your 2014.
    view full answer...
  • Wiring Connections for Hopkins Endurance on a 1997 Dodge Ram 2500
    According to my research the wiring for your 1997 Dodge Ram 2500 are for the following functions: Black/orange - Tail/Running Red/Tan - 12V Power Green/Red - Left Turn/Stop Brown/Pink - Right Turn/Stop Light Blue - Trailer Brake Purple/Black - Reverse Black - Ground This means that if you are installing the Hopkins Endurance Quick-Install # HM47210 you will want to connect the wiring from your Dodge Ram to the following wires on the Hopkins Endurance: Black/orange - Brown Red/Tan...
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  • Installing Roadmaster Flexo-Coil Wiring on a 2019 Jeep Wrangler Rubicon JL
    According to my research you can use the Flexo-Coil Wiring Kit # RM-15267 for your 2019 Jeep Wrangler Rubicon but I don't believe you will connect to the same color wires as shown in the linked video for this kit on a 2017 Wrangler Unlimited. From what I could find I believe that the running light should be a white and gray wire on your driver's side but a white and orange wire on the passenger side. The stop/turn signals should be found on the yellow wire for the driver's side and the...
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  • Troubleshooting New Brakes That are Weak After Adjustment
    If you have adjusted your Dexter Electric Trailer Brake Kit # 23-26-27 properly and you are getting no braking power with your override manual while your trailer is connected to your tow vehicle then I would start off by checking your 7-Way connectors for any corrosion or debris. If those look good the next step would be to determine if the brake controller signal is actually getting to the trailer or not. Using a circuit tester like part # PTW2991 test the pin in the 5 o'clock position...
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  • Installing the Red Wire from Prodigy P3 Brake Controller on a 2018 Subaru Outback Wagon
    Typically the brown wire on a 7-Way carries the running light function. If you were to connect the red wire from the brake controller harness, like what comes with the Tekonsha Prodigy P3 # 90195, then your trailer brakes would be active when you turn your headlights on. Because of this it is best to connect the red wire directly to the stop light circuit by the brake pedal on your 2018 Subaru Outback Wagon. If this happens to be a brown wire then all you need to do is use a circuit tester...
    view full answer...
  • Trailer Brakes Will Not Lock Up with Primus IQ Brake Controller # TK90160 in 2007 Silverado 1500
    The fact that your trailer brakes will not lock up at 20-25 mph speed does not necessarily indicate a problem with the brake controller. The best way to isolate the problem is to apply a circuit tester to the wires leading into one of the trailer electric brake assemblies to read the voltage reaching the brake. You can use a voltage tester like # BTMT15 to read the voltage being delivered to the brake assembly. You should read +12 volts or very close to it at each brake when the controller...
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  • Trailer Wiring Harness for a 2014 Ford Explorer
    Curt trailer wiring # C56172 is designed to fit a 2014 Ford Explorer that came with the factory tow package. If your Explorer does not have the factory tow package then the connectors for the harness will either not be present or they will not be functional. It sounds like your model does not have the factory tow package so you would need to use Hopkins harness # HM40285. It is also possible that the one connector you see and the one that is capped off are the connectors for the tow...
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  • With Trailer Connected Truck Reverse Lights and Trailer Brake Lights Are Not Working
    It sounds like you might have a few different issues going on here. First, we need to test the vehicle side 7-Way connector to make sure it is working properly. Use a circuit tester such as # PTW2991 to test the pins on the connector while someone sits in the truck and runs through the light functions. If something does not work then you will need to determine the problem. Check the trailer connector for corrosion inside and out. Corrosion can cause all sorts of issues, so can ground...
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  • Adding Heavy Duty 4/7-Way Connector to a 2014 Jeep Cherokee Trailhawk with Light Duty Tow Package
    The heavy duty towing package on the 2014 Jeep Cherokee Trailhawk looks to be the same as # HM40975-11998. You could use this set up and what you would do is cut off the 4-Way and splice in the wires to the harness included with # HM40975-11998. On the harness the red wire is left turn signal and brake lights. White is ground. Green is right turn signal and brake lights. Brown is running lights. The functions that will not be used are the blue wire for electric brakes, black for...
    view full answer...
  • Troubleshooting Trailer Wiring for Fleetwood Pop-Up Trailer and 2003 Mazda B3000 Pickup
    A potential cause for your issue is a weak ground connection. Trace the white ground wire from your 4-pole back to where it attaches to the vehicle frame. This ground must be secured to a clean and rust-free spot on the frame. If necessary sand off the rust/dirt from that grounding point and reattach the white ground wire or relocate it a new spot. If this does not correct the problem then I suggest you next test your existing 4-pole trailer connector on your Mazda to confirm it is...
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  • P3 Trailer Brake Controller Shows Trailer Connected with No Trailer and Voltage When Moved
    First, if the controller thinks a trailer is connected that is usually because there is something drawing power on the blue wire. To test this, sever the blue wire a few inches from the back of the controller. Then use a circuit tester such as # PTW2991 to test the end of the blue wire coming out of the controller. It should only show power when the manual override is pressed. If it shows power at any other time then there is something wrong inside the controller and it will need to be...
    view full answer...
  • Where to Tap Into Reverse Light Circuit to Install Trailer Connector Adapter with Backup Alarm
    To wire in the reverse light wire on Curt 7-Way connector # C57102 for the back up alarm to work you will need to tap into a reverse light wire behind a reverse light on your 1999 Dodge Ram. If you do not wish to tap into the wire there then you can trace the harness to a more accessible location. Then use a circuit tester such as # PTW2991, to find the correct wire before tapping into it. Be sure that the white ground wire on the 7-Way is attached to the truck frame. Otherwise the...
    view full answer...
  • How Does the Hopkins Agility Trailer Brake Controller Install on a 2003 Western Alpine RV
    The Hopkins Agility brake controller # HM47294 does come with a harness so that you can hardwire it into a vehicle. If your 2003 Western Alpine was built on the Ford F-53 chassis by any chance, there may be a plug in harness available that would make installation easy. If it is the F-53 chassis, there is a brake controller plug located behind the instrument cluster. It is difficult to get to though. Take a look at the picture showing where it is. You would use harness # HM47855 to plug...
    view full answer...
  • How to Determine Where to Connect Tow Bar Wiring for 2019 Chevy Equinox Premier
    To install the Universal Hy-Power Diode Wiring Kit # RM-154 on your 2019 Chevy Equinox Premier you will need to use a circuit tester like part # PTW2991 to determine what wiring colors for your tail lights carry which functions. Unfortunately we don't have a wiring diagram for your vehicle that I can pass along to you. Attached is an installation video on a 2018 Equinox that you can use as an example but I'd still test your wiring to make sure everything is connected to the proper circuit.
    view full answer...
  • Trailer Brakes Intermittently Turn On While Driving without Using Brake Pedal or Manual Override
    It is possible that there is a short somewhere that is intermittently kicking in due to vehicle/trailer position changes as you drive. The likely culprits are the trailer connectors on the vehicle and trailer. You will need to make sure that the connectors are clean and free of corrosion inside and out. To test the controller use a circuit tester such as # PTW2991. Sever the blue wire a few inches from the back of the controller and test the end coming out of the controller while fully...
    view full answer...
  • Trailer Harness on 1999 Toyota 4Runner Does Not Work
    Since this is the first time you have used the connector on your 4Runner, if it has been awhile since it was installed or if it is factory then there can be some corrosion build up inside the connector preventing it from working. This happened to a friend of mine recently. Scraping out the corrosion will help. Also make sure the main ground is connected to a clean and corrosion free bare metal surface. If that does not help then use a circuit tester such as # PTW2991 to test the vehicle...
    view full answer...

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Info for this part was:

Video Edited:
Dustin K
Installed by:
Cole B
Installed by:
Brent H
Written by:
Mary E
Video by:
Zach D
Updated by:
Erin H

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