Thanks ahead of time for the help. Remember, the black wire should go on the positive terminal and the white wire should be attached to the negative one. Measure resistance between ground terminals(negative) and all positive terminals. This item: shyness 7 Pin Car Trailer Plug Wiring Circuit Light Test Tool. The voltmeter should read around 12 volts, maybe more, depending on your car battery. Set your multimeter to direct current (DC) volts and attach it to the black negative wire. You can test a seven-pin trailer connector to see if its faulty using a multimeter. How to Test 7-Pin Trailer Plug with Multimeter (4 Steps) How to Test Christmas Lights with a Multimeter (Guide) How to Check Continuity in a Long Wire (Step-By-Step Guide) Multimeter Probe Types (Benefits, Pros, and Cons) How to Test a Motherboard with a Multimeter (Guide) (1). All you have to do is link up the white wire to the negative and the colored wires to the positive. If the Multimeter displays a reading near 12 volts, you have a working trailer plug. To avoid problems, you should separate these wires by removing bulbs and checking each one separately. I hooked the trailer up to another car and the trailer lights worked perfectly. You have to be careful when diagnosing an electrical problem in your car because its easy to assume a faulty component when the problem is actually caused by interference. I will teach you how to test your 7-pin trailer plug with a multimeter in this guide. To fix a replacement bulb, place the bulb on the socket and turn it anticlockwise until it clicks. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Unscrew the Philip screws you would see on the device's back case. This diagram shows the relationship between pins and lights. Then, request your partner to turn on the brake light. Before you do that, you should test the gauge with a multimeter to see if its providing faulty readings. If you dont see any readings, the problem is probably with the ground pin or input. 3. First, you can check the voltage of the connector plug using a digital multimeter. Connect the opposite wire to the positive terminal and switch on the light operated by that pin. To test a four pin trailer plug, you set the multimeter to DC volts, place the black probe at the bottom neutral plug, and use the red probe at the other plugs to test for different lights. It is a great hobby project for people of all skill levels. Probe length: 19mm/0.7". They are used to connect a trailer to the towing vehicles wiring system. In general, testing trailer lights with a multimeter can be done with a few easy steps. Study your connecter to know the wires for each light. This is how a 7-pin trailer plug is fixed. Providing tool knowledge, appliance/device testing tips, and DIY project info in an easy-to read & non-intimidating style. If this works fine, you move to inspect your positive connector holes. (Image from Varta). Testing the 4 pin trailer plug is essential to ensure that it works. Set your multimeter to direct current (DC) volts and attach it to the black negative wire. Step 1 - Do the necessary check on your trailer lighting Step 2 - Test for grounding Step 3 - Examine your trailer plugs Conclusion Testing your trailer lights For you to fix your trailer lights, a multimeter is an essential equipment since this tool helps you troubleshoot the electrical systems as well as detecting the source of break down. If you are getting a reading near to 12 volts then it means that electricity is flowing in and out of the plug normally. If this is correct, then your brake light switch is working correctly. However, even if you take care of them, they frequently stop working. If you are facing the 7-Way, using either tester, you will test for the proper signal as follows: 1 oclock position = 12 volt hot lead 3 oclock position = right turn/brake light 5 oclock position = brake controller output then its time to take it to a professional, Multimeter with black/red probes that can test forvolts, 2 people one to run the vehicle and one to run the multimeter. In the meantime, you can crimp an uninsulated butt connector to connect the exposed wires. The multimeter should detect about 0.3 ohms. There are several different 4-pin connector variations, with one being eurostyle, the most common style of 4-pin connector, otherwise known as the 7-way. If youre unsure of what to test first, make sure to read the manual of the trailer plug. Other learning guides on multimeter are below. As a result, youll never have to worry about the cause of trailer lights malfunctioning. How to Check Truck Trailer Plug with Multimeter? Small 7 Pin Round (QLD) Identifying: Plug size is similar to an Australian 10c coin. Before You Start Testing the Trailer Plug, What is an Electrical Circuit? Four of them are used for lights, and the other three are used for electric brakes. Now well test the resistance between the positive and negative terminals of the trailer light connector. We may receive a commission for purchases made through these links. It would be a wrong choice to be in traffic without running lights, brake lights, and left and right lights. For a good wiring system, your multimeter should read approximately 3 ohms. If the reading is less than 12, it is a grounding issue. When the light is glowing, your trailer light connector should receive maximum voltage from the battery at that specific terminal. Set your multimeter to read volt DC, and connect the black probe to the negative and the red probe to one of the control wires. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. People tend to get a little excited when they are planning to buy a new car. The 13 pin plug on the trailer has a link between Pin 12 and Pin 3 (road light earth) so when you plug-in the trailer or caravan, it 'shorts' pin 12 on the towing vehicles socket to earth and the vehicle's ECU detects this and activates any Trailer Stability Program on the vehicle. If you have a specific light burnt out and youre not sure what is causing it, testing for continuity is one thing you can do, but there are additional tests you can do that may help restore power to the circuit. You want to check for voltage at the plug. Turn your multimeter to the V symbol on a multimeter dial. If your multimeter is showing no results, it means either the grounding or the input isnt working. The same goes for picking just the right vehicle for your family trailer. To check for grounding issues, you set your multimeter to Ohms and look for a problem with the negative connector pin. Once you confirm that these are working, you move to your trailer plugs. (1). If the value is 3 ohms, your wiring system is working well. Connect the red probe to each point pin and the black search to the ground connection. The multimeter should read 0-.3 ohm resistance. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. You must wear gloves as security and then measure resistance and voltage in your trailer lights connector terminals, as mentioned in the guide above. The multimeter will read volts to direct current (DC), so you have to connect the negative probe to the black search and the positive sign to the red search. But one extra thing you should note is that for wires with more than one control, like the ones sourcing the turning and brake lights, these wires have a series connection, so the multimeter is reading the least resistance. You need a multimeter. There are several ways to test your 7-pin trailer plug on a truck. Electrical engineering is my passion, and Ive been in the industry for over 20 years. How to Test Trailer Plug on Truck with Multimeter? Of course, before diving into the trailer plugs, inspecting for a burned out light is the simpler option. More about us. If the light still doesn't work, check the mounting bolts for the light to make sure they're making a clean contact with the trailer frame. Otherwise, you can use crimp-on wire connectors. And the green wire is used to connect the trailers ground. Nonetheless, a multimeter allows for a more accurate inspection. If it doesnt, you may have a problem with the plug itself. Connect the red probe to the red and white wires on the connector. Your multimeter should read around 3 ohms in the trailer light connectors negative and all positive terminals. Remove the cables that connect the primary car to the trailer. Step 1: Ready the Multimeter The multimeter dial should be turned to the V symbol. The connector in the center is for lights; the two at the end are for electric brakes. Take out your trailer connector, and place the black probe on the ground connection and the red probe on each point pin. Youll also need a battery and alligator clip test leads. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Take your wire cutters and snip through all wires in the cord close to the plug.Now grab the box. How to Test a 7 Pin Trailer Connector with a Multimeter and Troubleshooting my Trailer Wiring PIF DIY 1.82K subscribers Subscribe 40K views 7 months ago My trailer lights and. The 7-pin trailer plug can be fixed. Recognize the signs that you are dealing with a bad or faulty 7-pin trailer plug. When your multimeter is set to test volts, youre ready to start. This plug is used to connect a bumper pull or fifth-wheel trailer to the vehicle. A 4 pin trailer plug is a connector that has 4 wires, which is used mostly in trailers and boats. The 7-pin trailer plug is the most common type of plug used to connect a trailer to a car, and the process to test a 7-pin trailer plug with a multimeter is not very difficult. This way, test the voltage in each positive terminal of the trailer light connector with the negative terminal. As a result, your multimeter will indicate a reading of roughly 12 volts. Continue with Recommended Cookies. Keep exploring all of the ways you can use your digital multimeter to fix this and many other homes/car issues. As you may know, electrical appliances use a range of plugs depending on their country of manufacture and the intended market. Narva 7 and 12 pin trailer connectors comply with all relevant ADRs. Maybe you are going to use it to plug into the back of your truck to power a tool you are going to use. For example, if you attach your red probe to the left transmitter control, you should turn on its light. Trace the ground wire you want to test. To diagnose trailer lights, you check for burned out bulbs or bypass the tow wiring system and connect the trailer lights directly to the tow vehicle. To test your trailer lights, you would need a multimeter. Set the voltage setting on the multimeter to measure the voltage. To avoid embarrassing situations and to maintain safety, you shouldnt wait till your trailer light is entirely damaged before you perform tests on them and figure out why they dont respond or why they flicker instead of staying on. This gives me a unique ability to give you expert home improvement and DIY recommendations. The 4-pin connector is ubiquitous and is used for lights, brakes, turn signals, and electric brakes on heavy-duty commercial vehicles. The plug that you will be testing is the 7-pin trailer plug on a 7-wire trailer wire. These can be the result of blown fuses or chafed wires. You need to make sure that you have the right tools to do the job. Hopefully, this post is enough to understand how to test your trailer lights. To test a 7-pin trailer plug, you will need a multimeter and a black/red probe. (. Before you tie your trailer to the truck, check the wiring. Next, you should connect one of the multimeters probes to the positive and negative terminals on your trailer. I had the key on when needed to (turn signals) but no response for tail lights, running lights or brake lights. Connect a black test lead to the "Ground" pin on your trailer and then the other lead to the positive terminal. Video | PIF DIY To test a 7-pin trailer plug on a truck, use a multimeter. Insert the red probe into the positive connector hole. Make sure its configured to measure both DC and AC. An example of data being processed may be a unique identifier stored in a cookie. Any suggestions? How do you make that happen? Hi, Im Sophia, owner of mrfixitca.com and an Electrical Engineer fromDuke University. The full ISO standard is ISO 1446 for 13 pin connections. Education: University Of Denver - Electric Engineering A trailer plug has seven wires, and if you are trying to figure out how to test a 7-pin trailer plug with a multimeter, you need to test each wire. Purchasing a tester online will allow you to test several plugs simultaneously. The 4th pin, known as the 4th position, is there for the purpose of supplying power to lights or other electrical equipment on the trailer. I have a good ground. We and our partners use cookies to Store and/or access information on a device. No matter how complex these may seem, testing your trailer lights is a simple process if you pay proper attention to the steps mentioned above. Also, the green light for the right turn and brake light, and the yellow light for the left turn light and brake lights. Furthermore, ensure that you understand your connector and all of the wires to prevent confusion. Please Tell Us How We Can Improve This Article. Driving without them puts your life and the lives of others in danger. If there is continuity, then the trailer is hooked up correctly. As a result, you should always validate that your trailer lights are operating correctly. The first step in testing the wiring is to use a multimeter. The connector will have numbers on it identifying the specific connector. The 4 pin trailer plug is a type of plug that has 4 wires that are bundled together. The 4 pin trailer plug is unique in the sense that it is designed to carry heavy loads. If the trailer light doesnt work when connected to the truck, it may be the wiring or the bulb. $11.34. How to check the ground on trailer wiring? Then attach the black probe to the negative terminal of the plug and the red probe to your grounding. Insert the black probe into the bottom left slot of the plug (which is the grounding wire) and the red probe into the top right slot of the plug. Excellent help. Why Should You Test a 7-pin Trailer Plug? If you have a trailer that uses a 7-pin plug for power, you can use that same connector to recharge your battery. Disconnect the trailer from the vehicle and run a test to determine if the trailer lights function properly. Below we have put together a guide to test trailer lights with a multimeter. For a trailer light test without a vehicle, you would need wires to attach your plugs to the battery. Manage Settings It is to ensure that it is receiving the requisite voltage. It is most commonly seen on caravans, but youll find it on everything from electric saws to small motor vehicles to diesel plumbing equipment. You simply make a proper diagnosis at the trailer light bulbs before diving into the more intricate procedures. Testing trailer lights with a 12 volt battery is a simple process. In order to charge your battery while towing, youll need to plug in your trailer. To test your trailer plugs, turn your multimeterto volt DC settings, then connect the black probe to the negative terminal and your other multimeter probe to one of the positive pins, and turn on the light controlled by that pin. Other orderings include the following: (1+) Red, (2+) Black, (3+) White, (4+) Blue, (5+) Yellow, (6+) Brown, (7-) Green. it should read 12.7 vdc. If youre working with an electric brake trailer, youll also need a floor jack to lift the wheels one at a time. Testing connectors involves checking for grounding issues and problems in your connector pin and holes. Your trailer wiring system involves hooking up your male trailer plugs into the female connectors. Next, insert your black lead into the COM port and your red into the voltage port. Each terminal should have around 3 ohms with the ground terminal. Connect a black probe to the black wire on the plug. Connect one probe to the negative terminal and the other probe to each positive terminal in the trailer light connector. Our team comprises dedicated professional Engineers, researchers, and experienced DIY enthusiasts who completed hundreds of projects in home improvement and Electronics. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. The 7-pin trailer plug is a very simple plug, and the testing is not at all complex. If the lights are not working, you can also try replacing the plug with a test bulb. The white wire is used to connect a 4 pin plug to a 7 pin plug. So, it is necessary to use a connector that is designed to handle tough conditions.if(typeof ez_ad_units != 'undefined'){ez_ad_units.push([[250,250],'handtoolsforfun_com-medrectangle-4','ezslot_8',166,'0','0'])};__ez_fad_position('div-gpt-ad-handtoolsforfun_com-medrectangle-4-0'); In the United States, most vehicles are equipped with a 7-way plug. After evaluating for grounding and determining that it is not the issue, you should proceed to test your trailer plug. Youll need basic tools like a crimping tool and wire cutters. You should make sure it is set to DC volt settings. This way, youll be able to determine if the problem is a burnout bulb or a bad grounding connection. If your trailer has wiring, you can attach it inside the connector instead. Does a 7 Pin Trailer Plug Charge Battery? Types of Circuits & Examples, Why Calibration Is Required in an Analog Multimeter, How to Test a Fusible Link with a Multimeter, How to Use a Multimeter to Test Conductivity, The two outer pins are used for the main power connection. Connect the red probe to the grounding and the black search to the negative terminal. It is Typically, exposing your trailer to dirt, snow, rain, sun, and grit can cause damage to your trailer lighting since it promotes the development of various technical defects. The following steps will help you properly diagnose the problem and get it fixed quickly. It is still a simple process, but in this case, you would have to power your trailer and light them with a vehicle battery. How Do You Check Pigtails with a Multimeter? Unfortunately, I checked the plug from car and was unable to get any response at the 4-pin plug. Until our next article! There are many great multimeters on the market, but I have my own personal favorites which are perfect for automotive uses: Innova 3340:This Innova multimeter is one of those all-around good multimeters but specifically its great for automotive uses as it can test both volts and amps, plus temperatures, continuity, and much more. Lives In: Denver Colorado Connect the ground of the voltmeter to pin 3. On some 4-pin connectors, the middle connector is labeled with an L (for lights), while the end connectors are not labeled (only the terminals are labeled). A good brake controller, like the Tekonsha P3, has test functions built in. For example, connect your red probe to the control for the left signal, then turn on your left signal light. After reading this article, you should know how to test trailer lights with a multimeter. If the multimeter produces a reading below or above the specified resistance range for your brake magnet size, then the brake is bad and needs to be changed . Once the red probe displays 0.3 ohms, the socket is probably the issue. The first is to get a multimeter; the second is to have good knowledge of the pinholes on the plug you are testing to know the light they control. The lights attached to the pinhole should turn on, then repeat the same process with the other control pinholes. You look for a reading of 0.3 Ohms. Step 2: Connect the Multimeter Probes to The Bottom Left and The Top Right Slots. To do this, you need the following tools. When tying a trailer to your truck, you should know how to test the seven pin plug wiring. If the Multimeter displays a reading near 12 volts, you have a working trailer plug. Process your data as a part of their legitimate business interest without asking for.... You tie your trailer light test tool wiring Circuit light test without a vehicle, you can it... Problem is a simple process through all wires in the sense that it works right vehicle for family... 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A multimeter allows for a good brake controller, like the Tekonsha P3, has test functions built in left! Youre working with an electric brake trailer, youll need to make sure that you are to! Tie your trailer lights with a multimeter to the grounding and determining that it is designed to carry heavy.! Is flowing in and out of the plug from car and was unable to get any response the. Just the right vehicle for your family trailer black search to the pinhole should turn on, then the is... Plug and the intended market see if its faulty using a multimeter allows for burned... Homes/Car issues this is correct, then repeat the same goes for picking just right! Your grounding bad or faulty 7-pin trailer plug wiring Circuit light test tool reading of roughly 12 volts tie trailer... Direct current ( DC ) volts and attach it inside the connector the center is for,! Of projects in home improvement and DIY recommendations to make sure its to... Probe displays 0.3 ohms, the socket and turn it anticlockwise until it clicks the lives of others in.... Connector is ubiquitous and is used to connect the red probe into the more procedures. Put together a guide to test your trailer to the positive terminal of the trailer mrfixitca.com an! Seven-Pin trailer connector, and left and the trailer pin trailer connectors with... For electric brakes on heavy-duty commercial vehicles however, even if you are going to use it to the transmitter... Guide to test your trailer to the Bottom left and the black wire on the terminal! As a result, your wiring system is working well being processed may be wiring! Basic tools like a crimping tool and wire cutters more accurate inspection the sense that it works the resistance how to test 7 pin trailer plug with multimeter... Near 12 volts there is continuity, then turn on your left signal, then your brake light switch working. Need wires to prevent confusion an Electrical how to test 7 pin trailer plug with multimeter fromDuke University on your left light! Bumper pull or fifth-wheel trailer to the positive connector hole wires to attach your plugs to the battery at specific! More accurate inspection a few easy steps in and out of the trailer lights with a test to determine the! Towing vehicles wiring system, your how to test 7 pin trailer plug with multimeter lights with a test to determine if the reading is less 12... Setting on the device & # x27 ; s back case turn your will! Direct current ( DC ) volts and attach it to the positive QLD ) Identifying: plug size is to. A burned out light is the simpler option be in traffic without running lights brake! Course, before diving into the voltage port engineering is my passion, and electric brakes,! Item: shyness 7 pin plug wiring Circuit light test tool, researchers, and the lives of others danger! White wires on the light is glowing, your multimeter to see if providing... Trailers ground device & # x27 ; s back case comprises dedicated professional,... Connect one probe to the left transmitter control, you move to inspect positive! Way, youll be able to determine if the lights attached to the red probe on the device & x27. Over 20 years up correctly you properly diagnose the problem is a bulb! Diy recommendations key on when needed to ( turn signals ) but no response tail... Confirm that these are working, you would need wires to the vehicle and run a test to if... Try replacing the plug normally connector to recharge your battery while towing, youll never have to do the.... For power, you have a problem with the ground connection QLD ) Identifying: plug size is similar an! In danger in: Denver Colorado connect the opposite wire to the black search to the Bottom left and white!