Cordless Circuit Tester

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• Troubleshooting Brake Controller and Trailer Not Having Brakes
  It sounds like you are having brake controller issues with your truck, and I can give you a number of troubleshooting steps to try and help you figure out the issue. I'm not 100 percent sure what you are referring to by "squeezing" the brake controller, so I can't offer advice there but there are numerous other things you can check. What you will need to do is find out if the issue is on the brake controller, truck, or trailer. To test the brake controller, sever the blue wire a couple...
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• Troubleshooting New 4-Way Not Working on Trailer
  If you installed a new 4-way and you have no lights working a bad ground is certainly a possibility but there are some troubleshooting issues you can do to try and resolve the issue, starting with simply checking the fuses on your tow vehicle to make sure they are all working and accounted for. If they are, in order to determine the specific problem you will need to use a circuit tester like the handy Cordless Circuit Tester # PTW2979 to test the connector on your vehicle after disconnecting...
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• Troubleshooting Trailer Parking Lights Not Working With 2003 Chevy Silverado
  I took a look at an online copy of an owner's manual for a 2003 Chevy Silverado and it looks like the fuse you are looking for is labeled "TRL PARK" and is in the upper left of the underhood fuse block. You should start there as that may solve the issue if the fuse needs replacing, otherwise there are a number of troubleshooting steps you can attempt. What you can do is use a circuit tester like the very handy Cordless Circuit Tester # PTW2979 to test the connector on your vehicle after...
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• Troubleshooting Brake Controller Not Working
  We do not carry this particular brake controller but there are a number of troubleshooting steps you can go through to find out what the problem is, which may not be the brake switch or the controller at all. You will need to 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...
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• Trailer Brake Lights Not Working With 2003 Ford F-250
  Since the relay for the trailer turn and stop is the same on a 2003 Ford F-250 we can rule that out but there are a number of other troubleshooting steps you are going to need to take in order find the specific issue. you will need to use a circuit tester like the very handy Cordless Circuit Tester # PTW2979 to test the connector on your vehicle after disconnecting it from your trailer. Check the wiring going into your harness from your tail lights to see if those wires are carrying the...
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• Troubleshooting Exterior Trailer Lights not Working
  The exterior lights of your horse trailer will be powered by the 12 volt circuit from your 7-way or an auxiliary 12 volt battery and since it seems the interior lights are still working the issue is likely the wiring is damaged or if you are using a fuse or power distribution box the issue could be something as simple as a blown fuse or a bad switch. You can use Circuit Tester # PTW2979 to determine if there is power getting to the switch or not and figure out exactly what wires are not...
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• How to Determine What Wire Functions are on 2007 Ford F-250
  If you take a look at the accompanying diagram, which is from our linked help article on wiring, you can see the common wire colors used by manufacturers. I want to stress that the only way to know for certain the functions of each wire on the 7-way of your 2007 Ford F-250 is to use a circuit tester such as # PTW2979. There are a couple reasons for this, notably because there is not a standard color for 7-ways in regards to function, and also because wiring may have been changed out in...
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• Locating Brake Wire on Horse Trailer to Resolve Brakes Locking Up
  The brake wire on a trailer is typically blue but this can certainly vary as trailer manufacturers tend to change up the colors they use at the factory and a previous owner may have also re-wired it using different color wiring. This is why it is always best to either try and trace the wiring back to its connection or test them by applying 12V power to the wire when trying to determine its function. The brake controller output pin on a trailer's 7-Way should be at the 5 o'clock position...
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• Do Trailer Wiring Colors Matter For Turn Signals/Tail Lights
  So with trailer wiring, the color codes aren't going to matter; all that is required is to know the functionality of the trailer wires. If you know what they are you're set, but the one thing you will want to do is verify the functions using a circuit tester such as # PTW2979. I have added some links below to help articles on trailer wiring which I recommend checking out as well.
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• Interior Lights Are Not Working
  For just one side of your interior lights not working, it is likely a damaged wire or maybe a switch that is connecting the lights on one side has failed. You'll need to test the wires coming out of your switches with Circuit Tester # PTW2979. If the switch is bad and needs to be replaced I have added a link below to our selection of rocker switches for you.
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• How to Determine Stop/Turn/Tail Light Wiring on Trailer for Peterbilt Log Truck
  Even though there are some generic wire colors for certain functions there isn't really a rule saying that those colors have to be used. The result is that any color can be used for any function which can get confusing. The best way to make sure that you have everything connected properly is by using a 12V power source (like an external battery) to test the wires on your trailer so you know what function each one goes to. Ground the negative terminal of the battery and use the positive...
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• 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 function...
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• Interior Lights Not Working on a 1998 Sooner Horse Trailer
  If all of the other functions on your trailer are working correctly, then you most likely have a short or a bad ground on the wiring that your interior lights are connected to. You can trace it all the way to the trailer connector on your horse trailer and look for any places where the wire might be bent, damaged, corroded, or exposed and replace it or fix it. Another way to test and see if that is the problem is to test the pin on your tow vehicle side connector that is used for 12V...
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• Troubleshooting Trailer Lights Working After Trailer Tongue is Moved Up and Down
  If you are having to wiggle wires around before they start to work on your trailer then you definitely have a short or a bad ground somewhere on your tow vehicle or trailer. It can also mean that you have corrosion somewhere on your wiring as well. Start off by checking the connectors and make sure that they don't have any corrosion or debris built up. You can determine which one it is by using a Circuit Tester # PTW2979 to test each of the functions on the connector for your tow vehicle....
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• Trailer Lighting is Getting Power But Lights are Not Working When Connected to 2008 Chevy Silverado
  If you are getting power to the connector on your 2008 Chevrolet Silverado and you have tested and found that there is power on the wires that go to the lights themselves, then it sounds like you have a short somewhere - most likely near the lights. You can verify this by using an alternate power source, like the battery from your Chevy, and test the different functions on your trailer connector. You can also check the connector on both your Chevy and your trailer to make sure there is...
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• 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.
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• Troubleshooting Turn and Brake Signals That Only Come On with Running Lights
  The first thing I recommend doing is using a circuit tester like # PTW2979 to test for power on the tow vehicle side 4-Way connector. Have a buddy sit in the vehicle to go through the different lighting functions while you test the corresponding pin on the 4-Way for power. You will want to make sure that you are getting power at the correct pin and that you aren't also getting power with the other pins. If you test the connector and the results are similar to the issue's you're seeing...
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• Troubleshooting Trailer Wiring
  I'm not sure what you are using or what vehicle you have so I'll have to give you general troubleshooting tips. 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...
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• Troubleshooting Headlights Going Off With Trailer Wiring Installed
  A headlight should not go out due to trailer wiring being installed; the only reason this might happen is if there is somehow a short on the circuit for the running lights, which is connected to the headlights. You may also simply have blown a fuse for one reason or another so check the owner's manual for your vehicle and see if you have a blown fuse that simply needs to be replaced. I have added links to a couple help articles on wiring which I strongly recommend taking a look at.
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• Troubleshooting Trailer Lights That Come On When Truck is Turned Off
  I recommend starting by testing the connector on your truck with a circuit tester like # PTW2979. This will help you quickly narrow down the possible locations of the issue. Have a buddy sit in the cab and run through the lighting functions while you test the appropriate connector pin for power. You should only get power at a specific pin when the corresponding function is activated (power at the left turn/brake light pin when that function is on, etc). If you find that you are getting...
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• 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...
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• Troubleshooting No Brake Output Power on Truck
  According to the online owner's manual for your 2009 Chevy Silverado there is a fuse located in the #6 position inside the underhood fuse block that's dedicated to the factory brake controller wiring. You will want to check this fuse and replace if needed. If this doesn't resolve the issue then there are a couple of other things you can look at. The first and easiest thing to check is how you're actually testing the brake controller. If you have a proportional controller it's important...
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• How To Determine Functions of Wires to Install Trailer Connector
  I really wish there was some universal color code for wiring as that would make everything a bit easier but unfortunately there isn't so really the only way to use a circuit tester and test the wires by function. If you don't have a circuit tester the very handy Cordless Circuit Tester # PTW2979 would be my strong recommendation due to how easy it is to use. I have also added links to a pair of articles on trailer wiring which I highly recommend checking out as they contain a lot of very...
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• Troubleshooting Trailer Wiring With 2008 Ford F-450
  For the issue with your running lights test the connector on your vehicle with Circuit Tester # PTW2979 or a similar one after disconnecting it from your trailer. If the signals going to your harness are okay, you'll need to test the signals coming out of the harness, and if they are correct then your issue is likely going to be with the trailer side wiring. You will also want to check both your vehicle and trailer connectors for corrosion, which can be green or white in color. A build-up...
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