Circuit Tester Kit

Circuit Tester Kit

Item # 40376

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Draw-Tite Tools for Wiring - 40376
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Product Images

Draw-Tite Tools for Wiring - 40376
Draw-Tite Circuit Tester Wiring - 40376
Circuit Tester Kit Circuit Tester 40376
Draw-Tite Tools for Wiring - 40376
Circuit Tester Kit Circuit Tester 40376
Circuit Tester Kit Circuit Tester 40376
Draw-Tite Wiring - 40376
Draw-Tite Wiring - 40376
Draw-Tite Tools for Wiring - 40376

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  • Tools for Wiring
  • Testers
  • Circuit Tester
  • Draw-Tite
Circuit Tester Kit Lowest Prices for the best wiring from Draw-Tite. Circuit Tester Kit part number 40376 can be ordered online at etrailer.com or call 800-298-8924 for expert service.


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  • Reviews (17)
  • Q & A (2386)
  • Videos (2)
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Draw-Tite Wiring - 40376

Circuit Tester Kit


Features:

  • Heavy-duty tester signals with a light and a buzzer
  • Tests low voltage up to 28 volts
  • Finds electrical shorts
  • Checks circuits from a distance
  • Checks polarity
  • Checks battery drain
  • Kit includes:
    • Alligator clip
    • Hook


40376 Circuit Tester Kit






Video of Circuit Tester Kit


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




Video Transcript for Circuit Tester Kit Review

Today we are going to show you part number 40376, this is the Ultimate Circuit Testing Kit. You can see the kit comes with three parts to it, obviously the tester itself here, the alligator clip that will actually go on to the end here. You also have the hook that goes over the end which goes around the wire and pierces the wire to test the wire also. This is the larger alligator clip you use for the ground. The way this unit identifies the circuits working, it does it in two different ways, it actually lights up and it actually makes a sound. We will demonstrate that here with this light we have hooked up to a power supply. This is the ground so this will go to the ground of one of the lights that you are working with. This probe here will actually go to the wire itself. We will use our hook here, and we will go ahead and just test the wire. Just squeeze it gently and you hear a tone and it lights up. What is also nice about this, if you actually reverse the polarity of this, it will reverse the ends and tell you the polarity.

We will use the small alligator clip here. We will attach it to our ground here and our original ground to the power supply here. You can see it just lights up, so that tells you that would be the ground and this would be the power wire. It helps determine the polarity, if you are not sure which end of the circuit you are on. You can see this is a nice heavy duty unit, these are the ones we use in our own shops, and that is what you have for part #40376.


Customer Reviews

Circuit Tester Kit - 40376

Average Customer Rating:  5.0 out of 5 stars   (17 Customer Reviews)

Circuit Tester Kit

- 40376

by:


This tester is well made and definitely worth the money. Makes troubleshooting wiring problems a breeze. 84363



- 40376

by:


Very nice tester. Heavier duty than the cheap ones you buy at local retail stores. I like the fact that it also has the audible tone along with the light. 33136



- 40376

by:


Product were just explained. always a great job. i enjoy doing business with etrailer. 64106



- 40376

by:


This is my second Lisle circuit tester. I purchased to replace a unit I lost. These are very well made and worth the extra spend. The Customer Service from e-trailer is second to none and I'm a repeat customer due to the help these folks will render. 228513


Comments

Still works well and is still in great shape. Thanks for asking.

Scott P - 09/29/2016

21328

- 40376

by:


Well made, clear instructions and very useful for sorting out trailer wires. If you have several trailers and multiple towing vehicles this is real handy! 413164



- 40376

by:


I have placed several orders with e-trailer over time and keep returning. I have gotten ffast response on questions and all orders have been filled correctly an on time. 274120



- 40376

by:


This really is the ultimate circuit tester! The audible feature is a huge benefit when working alone and energizing a circuit remotely.... saved me multiple trips between truck cab and trailer tail lights! When working on trailer light circuits, this is a must have tool! 84638



- 40376

by:


Excellent service and attention to detail. I would highly recommend purchasing from etrailer. Prices are great and they have a wide selection of information that helps with the purchase decision. Very impressed. 551374



- 40376

by:


Purchased this to troubleshoot existing truck wiring and wiring I installed. Much more convenient than using my volt-ohm meter (VOM). 585992



- 40376

by:


Excellent quality circuit tester. Can check battery drainage and troubleshoot wiring shorts. 498087



- 40376

by:


worked great for the purpose check wiring on trailer 422465



- 40376

by:


Great product 376271


Comments

Great product

Kej263 - 05/04/2018

38106

- 40376

by:


Ordered several electrical connectors,wire and a wire tester .. all items came in good condition ,looking forward to using the tester as soon as I can I am sure it will do the job. 359795



- 40376

by:


Looks good 235043



- 40376

by:


This circuit tester was worth every penny. The audio and light indicators took all the guesswork out of the wiring. It made it easy to identify turn signal and brake wires and I was able to test for proper functionality in my trailer contact once everything was installed. Highly recommended. 180242



- 40376

by:


High quality equipment! Thanks etrailer.com for the excellent service. 66038



- 40376

by:


Great tester 31427


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17

Ask the Experts about this Draw-Tite Wiring
Do you have a question about this Wiring?


  • 7-Way RV Trailer Connector Wiring Diagram
  • When wiring a trailer connector, it is best to wire by function, as wire colors can vary. We have an excellent wiring diagram on our website, I will provide you a link so you can look at it. If you are looking at the inside of the trailer connector where the wires mount to the terminals starting at the notch at the top and working clockwise: 1:00 is Black and 12 volt power 3:00 is Green and Right Turn and Brake 5:00 is Blue and Brake Controller 7:00 is White and Ground 9:00 is...
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  • Troubleshooting No Running Lights on Trailer but Turn Signals and Brake Lights Work
  • The 4-way on your trailer is what's known as a wishbone connector like part # A35W42B. Two of the wires are the running light circuit which is a little easier to install since you can run one down each side of the trailer. This way you don't need a jumper wire to go from one side to the other. A wishbone 4-way is compatible with a standard 4-way so your problem is somewhere in the wiring itself. I would start by checking the 4-way on the truck with a circuit tester, like part # 40376....
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  • Electric Trailer Brakes not Working
  • There are a number of reasons why the brakes on your trailer may not be working. Lets start with the easiest things to check. First, check the vehicle and trailer connectors for corrosion. This can cause a short inside the connector and the brake feed circuit and ground are at the bottom of the connector so moisture affects these connections first. Next, check the ground wire on the vehicle and trailer connectors, trailer brake magnets and the brake controller itself. If there is...
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  • What is the Factory Wiring Harness Color Code for a 2007 Chevy Silverado
  • The colors that GM typically uses for their factory trailer wiring are as follows - Dark Green - Right Turn/Brake Lights Yellow - Left Turn/Brake Lights Brown - Tail Lights White - Ground Light Green - Backup Lights Blue - Electric Brakes Red/Black - 12 Volt Power We had a 2007 Chevy Silverado with the factory trailer wiring on our lot, so I went out and verified that it had the same color code. I also noticed a white tag on the wiring harness that listed the functions of...
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  • Troubleshooting Electric Trailer Brake System on Trailer Towed by Chevy 2500 Series Truck
  • Discovering why the trailer brakes are not getting power will be a process of elimination. I am not aware of what you have and have not checked, so I will describe the whole troubleshoot process. Start with the brake controller itself. Is it properly adjusted and leveled (if necessary) according to the instructions? Is it getting power? To determine if the controller is receiving power, you can use a circuit tester like part # 40376 on the black wire that feeds the controller to ensure...
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  • Troubleshooting Turn Signals Not Working with Running Lights On on a Utility Trailer
  • First, check the trailer wiring harness on your tow vehicle with a circuit tester, like part # 40376, and make sure all of the functions are working correctly without the trailer connected. Make sure to test with the running lights on and off to be sure. If it is not working correctly you will most likely have to replace the taillight converter. If it is working correctly, turn your attention to the trailer. It does sound like a weak ground, or a short circuit issue, because when you...
    view full answer...

  • How To Wire LED Stop/Turn/Running Light
  • You should have 3 wires at the rear of your LED light, or from a pigtail like part # A47PB, that plugs into a light like part # STL22RB. The red wire will be connected to your stop/turn circuit on your vehicle. The black wire is spliced into your running lights, or the lights that are turned on your vehicle when the headlight switch is on. The white wire is your ground and needs to be attached to a clean, bare metal surface. It may help using a circuit tester like part # 40376,...
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  • How To Charge Trailer Battery On Dump Trailer Using The 7-Way Trailer Connector
  • You will want to use a circuit tester like part # 40376, and check the # 4 terminal on the back of the 7-way trailer connector on your trailer for power. This is the 12 volt power terminal so there should be power to that terminal. You will need to run a 10 gauge power wire like the, # 10-1-1, from the # 4 terminal (12 volt) on the 7-way trailer connector on the trailer to the positive terminal on the trailer battery. This will allow you to maintain a charge on your trailer battery,...
    view full answer...

  • Troubleshooting Right Turn Signal Not Working on Trailer Taillights
  • First, disconnect the trailer from the tow vehicle so you can check the vehicle side connector. Using a circuit tester like part # 40376, test the functions of the connector; specifically check the right turn/brake, to make sure the signal is making it to the connector. If it is not working at the connector, there might be a fuse blown or missing in the power distribution box under the hood. Also, make sure both connectors are clean, and free of any dirt or corrosion. This very well...
    view full answer...

  • Wiring Configuration For 7-Way Vehicle And Trailer Connectors
  • I have attached a photo that details the wiring connections for a 7-pole round pin connector. It also includes the vehicle side wiring as well. I have also attached a photo of the 7-way blade style connector as well. The center plus is an auxiliary 12V circuit. I do recommend using a circuit tester like part # 40376 and test each wire on the vehicle to make sure you have the correct configuration on your connector. I have also attached a link to a helpful article about trailer wiring...
    view full answer...

  • Troubleshooting Trailer and Truck Lighting Problems When Trailer 7-Way is Connected
  • Thank you for providing a thorough description of the truck and trailer lighting issues you're having. The various problems you describe COULD be related to the same issue, corrosion in the trailer connectors, but there may also be multiple things you'll need to attend to. The best way to troubleshoot your concerns is to unplug the trailer from the truck's 7-way and then to test each one individually. Since your RV is used, it's wiring is my prime suspect. Step one for troubleshooting...
    view full answer...

  • Trailer Fuse Locations on a 2015 Chevy Silverado 1500
  • If you are looking for the fuses on your 2015 Chevrolet Silverado 1500 that are tied to your trailer wiring then those will be in the fuse department in the engine compartment. You can find this information as well as a list of what all the fuses are tied to in your copy of your owner's manual. 1 - Trailer Brake 2 - Trailer Battery 14 - Trailer Stop/Turn Lamps, Left 15 - Trailer Parking Lamps 16 - Trailer Back-up Lamp 17 - Trailer Stop/Turn Lamps, Right 64 (Relay) - Trailer Parking...
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  • How to Determine the Factory Trailer Wire Functions on a 2005 Ford F-150
  • I may have some information that will help, however, vehicle manufacturers are notorious for changing the wire colors on their factory trailer wiring, so the best way to determine the function of each wire is by testing. To test the wires, I recommend using a circuit tester like part # 40376. Find a good ground for the tester and test each wire as a helper activates each light function on the truck. We had a 2006 Ford F-150 on our lot with the factory tow package wiring, so I went to...
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  • Brake Controller Wiring Instructions for the Tekonsha Voyager # 39510
  • Depending on your vehicle year make and model, I will be able to provide instructions for wiring the Tekonsha Voyager brake controller. I have included the instructions for the Voyager, an FAQ article that features a basic diagram near the middle of the document, and an article on wiring a brake controller from scratch. The wires coming out of the Voyager attach as follows. The red wire attaches to the brake light switch wire that carriers a signal only when the brake pedal is pressed....
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  • Tekonsha Voyager Brake Controller Not Activating Trailer Brakes When Brake Pedal Is Pressed
  • Yes, we can help you test your brake controller and determine if the controller is bad or if there is a wiring issue that is causing the problem on your 2003 Ford F-250 pickup. Lets start with the easiest things first. Be sure that when you are testing the trailer brakes with the brake pedal that the vehicle is moving. The trailer brakes will not apply with the brake pedal if the vehicle is not moving because of the proportional sensor. The first thing I would check is the red wire that...
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  • Wiring For 7-Way Connector on 2004 Chevrolet Silverado 2500
  • On your 2004 Chevrolet Silverado 2500 the factory wires should be light green, dark green, blue, yellow, red, brown, and black. The functions of those wires should be as follows: light green - reverse lights dark green - right turn/brake blue - electric trailer brakes yellow - left turn/brake red - 12 volt power brown - running lights black - ground I would also recommend to test the functions of your wires with a circuit tester, part # 40376, to verify the function of the...
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  • Converting From 7-Way Round to 7-Way Flat Connector
  • We do offer the Pollak Trailer Connector Adapter, # PK12-724, which converts a 7-pole round connector to a 7-pole flat connector. This adapter works for tow vehicles with combined taillight wiring, meaning that the turn signals and brake lights run on the same pin. If by chance your tractor has separate taillight wiring, meaning that the turn signals and brake lights run on separate pins, you will need to add a converter, like the Tow Ready, # 119130. Just cut off the 4 way end and wire...
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  • Connecting 5 Wires From a Trailer to a 7-Way Trailer Connector
  • The best solution for your situation would be to use a circuit tester, like part # 40376, to wire your trailer wires to a seven way trailer connector, like part # A7WCB. Wiring by function is the best way to make sure you have the trailer connector wired correctly. Be sure you know what the black wire function is on the trailer. It will probably be for a twelve volt battery or for reverse lights, but it could be used for something else. The location for the black wire in the connector...
    view full answer...

  • Trailer Tow Package Turn Signal Fuse and Relay Locations on a 2010 Ford F-150
  • There is one fuse location and two relay locations you will want to check in the power distribution box in the engine compartment. First, check the 20 amp fuse in location 45. This is the Trailer tow stop turn relay feed. If that checks out fine, then check the left hand stop/turn relay in location 37 and the right hand stop/turn relay in location 38. The best way to test a relay is to replace the existing relays with relays that you know are in good working order. If the fuses and...
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  • Which Wires Are Used When Installing Marker Lights On Trailer
  • For a typical trailer wiring you will have a brown and green wire for the right hand side of the trailer and brown and yellow wire for the left side. If this is a new wiring installation and you are installing wiring like part # A35W42B, the brown wire that runs down each side of the trailer is for the marker lights and tail lights. The yellow and green wires are for the left and right turn signals. You will want to tap into the brown wire for the marker lights. If you are adding...
    view full answer...

  • How to Troubleshoot a Trailer Blowing the Running/Taillight Fuse Only
  • Since 6 of your trailers are not having problems with the 7-Way connector on your vehicle, the problem must be in the 7th trailers wiring. I would start with making sure all of the ground connections are securely attached to clean, rust and corrosion free surfaces, just to be sure, although it sounds like a short circuit issue. Then, I would check the 7-Way trailer connector. Take it apart and check inside to be sure that the wire connections are not shorted somehow to the taillight...
    view full answer...

  • Trailer Brake Controller Wont Light Up and Trailer Brakes Do Not Work Even with Manual Override
  • When a brake controller like your Draw-Tite Activator # 5100 does not light up to indicate that is senses a connected trailer, then often the problem is in either the vehicle-side or trailer-side connectors. Since the manual override does not activate the brakes then we know there is a problem with the output signal reaching the trailer. First, check both the vehicle socket and the trailer plug for signs of corrosion (even slight green or white discoloration) on the electrical contact...
    view full answer...

  • Left Turn Signals Not Working When Hooking Up Utility Trailer To Truck
  • Sounds like it is a ground problem. I would start with checking the ground of the left tail light of your utility trailer to make sure it is making a good ground. The tail light assembly is grounded to the trailer by either a separate ground wire to the frame or by the bolts of the tail light assembly being attached to the frame of the trailer. You will want to make sure the tail light assembly is fastened to the metal trailer frame securely and making a good ground. If it has the ground...
    view full answer...

  • Wiring Harness for 1999 Ford F-250 and F-350 Super Duty
  • If your 1999 F-250 Super Duty pickup had a factory 7-Way wiring harness and the, under vehicle connector has not been damaged you could use the Ford Replacement OEM Tow Package Wiring Harness, 7-Way (Super Duty), item # 118243, and if you had a factory 6-Way connector then you could use the Ford Replacement OEM Tow Package Wiring Harness, 6-Way (Super Duty), item # 20029, to replace your pigtail. If you would like to hard wire a new connector to the truck then you will need to use a...
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  • Where To Attach Blue Wire From 5 Wires on Trailer When Installing a 7-Way Connector
  • When wiring a 7-Way on your trailer with 5 wires, your green wire will be right turn/brake, the yellow wire will be left turn/brake, the brown wire will be the taillights, and the white wire will be the ground. You will want to find out if the blue wire on your trailer is needed for 12 volt power for trailer accessories, for electric brakes, or for a reverse brake lockout, if your trailer has surge/hydraulic brakes. Looking at the rear of the 7-Way connector, if you need the blue wire...
    view full answer...

  • Wiring Color Code On Ford Motor Home With 7-Way Connector And Car To Be Towed Has 6-Way Connector
  • The 6-wire and the 7-wire connectors will have the same color codes on six of the wires. The green wire is right turn/brake, the yellow wire is left turn/brake, the white wire is the ground, the brown wire is the taillights, the blue wire is electric brakes, and the black wire is the 12v power. The 7-way motorhome connector will have an extra auxiliary wire (purple) on the center pin that is used for reverse lights, 12v power, or reverse lockout for trailer brakes. There are two...
    view full answer...


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Info for this part was:

Expert Research:
Michael L
Video Edited:
Zack K
Video Edited:
Andrew K
Expert Research:
Robert G
Expert Research:
Patrick B
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
John H
Expert Research:
Adam R
Expert Research:
Jeffrey L
Photos by:
Zach O
Updated by:
Sarah W

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