See what our Experts say about this Hopkins Trailer Wiring

• Can You Use The 3rd Brake Light Logic Module With A 4-Pole
  For your 2021 Chevrolet Silverado you will have to splice into the factory wiring to use the 3rd Brake Light Logic Module # PP20-702 to connect the left and right turn signals, along with the green wire. You can also combine this harness # PP20-702 with a 4 pole harness like the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector # HM38138.
  view full answer...
  
• How To Wire License Plate Light/Bracket With 3 Wire Connection
  Most Trailer License Plate Lights with a Bracket like the Optronics # LPL55CB you found are only going to have 2 wires a power and ground for the light. It looks like yours has either an additional light for either a reverse light or brake light. While I cannot tell who manufactured your light you are most likely going to have to test the light with a 12 volt battery to determine which wires are power and for which function and which is the ground. Typically white or black are the most...
  view full answer...
• Tracker Boat Trailer Wires With 7 Wires Connecting Into A 4 Pin Plug
  It could be possible that your 2012 Boat trailer is wired with a wishbone style harness. Similar to Item # A25W2GWB. This type of harness just allows the installer to run each side separate rather than splicing and running extra wires across the bottom of the trailer. Your best bet may be to test each wire function before cutting. You cannot get trailer brakes from a 4 pin connector which is why I am leaning more toward it being a wishbone. Once you determine the proper functions all you...
  view full answer...
• Availability of 4-Way Male to 4-Way Male Wiring Adapter
  Nobody makes that exact adapter but you can put one together yourself pretty easily. All you need is a 4-way plug and lead like # HM38138 along with an additional connector # HMC20031 to add to the other end. Let me know if you have any other questions.
  view full answer...
• Wiring Parts Needed to Power 3rd Brake Light on 2020 Toyota Tacoma Topper Shell
  We definitely have the wiring parts and connectors to help you out but you will need to do some splicing to accomplish this as there isn't a plug and play type adapter. Here are the parts I recommend: - 3rd Brake Light Logic Module # PP20-702 - Pollak Complete Assembly 2-Pole Connector # PK12200 - Deka Heat Shrink Butt Connector Kit # DW05744-5 - 18-Gauge 2-Wire Bonded Parallel Conductor Wire # SWC97FR (sold by the foot) The Logic Modul connects to your turn signals and feeds the...
  view full answer...
  
• What Does Some Trailer Wiring Have 2 Brown Tail Light Wires
  Common 4-pole trailer wiring like # HM38138 uses one wire, the brown one, for the running lights on both sides of the trailer. Sometimes what is called a 'wishbone' harness is installed on the trailer and this simply uses two separate running light wires - brown with yellow for left and brown with green for right - to make it easier to connect to the trailer lights since that way no jumper wire will be needed to cross from one side to the other. Some examples of wishbone style 4-pole...
  view full answer...
  
• Solution for 4-Way Adapter With 4-Way Flat Male End and 4-Way Round Male End
  Your typical 4-way flat to round adapter like the # ADP001 is the opposite of what you need on both ends. Although nobody makes an adapter like this, you can easily make your own. For the 4-way flat trailer end connection you can use the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long # HM38138. You can cut the wiring harness down if you want it to be shorter but this gives you a decent amount of wire to work with. Then you will need the RoadMaster 4-Wire...
  view full answer...
  
• Replacement Wiring on Bully Lighted Hitch Step
  To replace your wiring on your Bully hitch step # CR-600LED I recommend the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector # HM38138 along with heat shrink connectors # DW05743-5. For added protection you can add a wire loom like # 7509-1 sold by the foot. The wires of this harness have the following functions for you to match up to the wires in the step. White: ground wire Yellow: left turn/brake light Green: right turn/brake light Brown: tail lights
  view full answer...
• Do 4-Way Connectors Have a Power Wire
  Trailer and vehicle 4-way connectors like you'll find with the 4-Way Flat Trailer Wiring Kit - Vehicle and Trailer Ends # HM48205 do not actually have a hot - or power - wire. As you can see by the cut out I added of the linked help article on trailer wiring (which I highly recommend checking out), a 4-way will activate running lights, brake lights and turn signals. I have added a link to our entire selection of trailer end 4-way connectors for you to take a look at.
  view full answer...
  
• Converting A 5 Wire 4 Way Trailer Connector To Vehicle 4 Way Flat
  It sounds like you have a separated wiring setup with 5 wires - yellow, yellow brown, green, green brown, white. Typically, yellow is left turn / stop, green is right turn / stop, yellow brown is left running light, green brown is right running light, white is ground. You convert this to a standard 4 way by wiring the 5 wires to 4 flat harness # HM38138. This allows you to wire up all of your trailer wires color for color and then simply plug it into the vehicle's 4 way connector. The...
  view full answer...
  
• Can 4-Pole Wiring Be Submerged Underwater
  4-pole wiring like the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector # HM38138 can technically be submerged underwater but you would want to ensure that the connections are all waterproofed with heat-shrink butt connectors, like # DW05744-10, for the bare wires and some Dielectric Grease # 11755 on the 4-Pole connectors.
  view full answer...
• How To Hardwire A 4-Way Harness On A Small Utility Trailer
  In order to wire a 4-way harness onto your trailer, you will need a few simple items. The first of which will include our Deka Heat Shrink Butt Connector part # DW05744-10 and the Electrical Connector Dielectric Grease part # LT37534. The rest of the tools needed for this install should be fairly common in most toolboxes. Before you install the wires, you will need to strip back a 1/4" of the jacket from each wire and place them into opposite ends of the butt connector. After you have...
  view full answer...
• What Gauge Wire does 4-Way Trailer Wiring Use
  Typically 4-way wiring consists of 18 and 16 gauge wires. For a 4-way that has all 16 gauge wire you would want the Wesbar 4-Pole Flat Connector # W787264. The part # HM38138 uses 18 gauge for all wires but the white that uses 16 gauge.
  view full answer...
  
• 4-Way Trailer Wiring Recommendation that Uses all 16 Gauge Wires
  For a 4-way that has all 16 gauge wire you would want the Wesbar 4-Pole Flat Connector # W787264. The part # HM38138 uses 18 gauge for all wires but the white that uses 16 gauge.
  view full answer...
• Recommended Plug to add Lights to Trailer Tailgate
  In order to add lights on your trailer's tailgate that will allow you to remove it, you can use 2 Wire Loop # 9651P. What you would want to do is cut it in half and use one side for your tailgate and one side for your trailer. I've added a link to a video review for you to take a look at as well.
  view full answer...
• Converting Euro 7-way To Standard 4-Way Flat Trailer Connection
  I am not familiar with the bike rack with lighting, however, you can rewire the 7 pin euro by function to the 4-way flat. I recommend using the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long # HM38138 along with quick splices like # SWC501925-1 or butt connectors like # DW05744-5. The 4-way functions are: White=ground wire Yellow=left turn/brake light Green=right turn/brake light Brown=tail lights I've attached a photo of the Euro functions for you.
  view full answer...
  
• Replacing 4-Way Flat Connector With No White Ground Wire Causing Lights To Turn Off
  You are correct that you need a ground wire for your 4-way flat connector. When you are hitting bumps the coupler for the ball has a small amount of play inside which is causing your lights to turn off and on. The Hopkins Wiring Harness # HM38138 will give you a short 4' lead which you can splice into your trailer wiring and run the white wire to a good ground location on the trailer. This will ensure a good solid ground connection for the wiring on the trailer. The Heat Shrink Butt Connectors...
  view full answer...
• Can Trailer with Brown Yellow and Brown Green Wires Run to Standard 4-Way
  Yes you would be able to use your current trailer wiring configuration with a standard 4-way that only has 4 wires like the # HM38138 that you referenced. Basically the yellow brown and the green brown wire would wire directly to the single brown wire of the 4-way and the other colors would match and you'd be set. What you have now is a wish bone setup that just has a separate wire for the running light circuit for each side of the trailer. We have 4-ways that are setup for this with the...
  view full answer...
• Troubleshooting Malfunctioning Trailer Lights
  This will depend on the year, make, and model of your truck, but there is typically a number of fuses for towing a trailer. You will want to check your owner's manual for the specific fuse locations for these functions. If the fuses all look good, however, it may be something else. Using a tester, like the # PTW2993, engage the right blinker and check the output on the 3 o'clock position of a 7 Way plug, or the green wire port on a 4 Flat plug. These will both handle the passenger (right)...
  view full answer...
• Adding A Trailer Hitch Receiver To A 2022 Vanleigh RV Beacon 39FBB 5th Wheel Trailer To Triple Tow
  To know which adjustable width trailer hitch will fit your 2022 Vanleigh RV Beacon 39FBB fifth wheel trailer you'll need to measure the distance between the inside of your frame rails. The Curt Adjustable Width Trailer Hitch Receiver for RVs # C13704 you were looking at fits a frame width of 22" to 66" Wide and has a 5,000lb GTW. If you can get me the frame width for your trailer I can find the correct fit for you. You'll also need a 4-pole connector to transfer your braking and turn...
  view full answer...
• Can You Connect the Thinline LED Trailer Tail Light Red Wire to both Green and Yellow Wire
  I believe what my friend Rob was referring to when he said to connect the red wire from your Thinline LED Trailer Tail Light # STL59RB to the yellow and green wires is to connect it to the yellow and green wires of the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector # HM38138. From there you can plug the Hopkins connector into your vehicle wiring harness for power if you are using this on a cargo carrier or other hitch mounted accessory. This process will not harm your vehicle...
  view full answer...
• Troubleshooting Turn Signals Not Working on a 4-Pole Setup
  The first 2 things that you want to check when experiencing wiring problems is all of your grounds and the connectors on both your tow vehicle and trailer. You will want to make sure that the grounds are secure and have a metal-to-metal contact. Sometimes even some paint can cause lighting issues. To replace a damaged connector on your trailer you will need part # HM38138; for your tow vehicle you can use part # C58044. If all of that looks good then you will want to test the wiring on...
  view full answer...
• Parts Needed to Re-Wire European Trailer to RV-Style Trailer Wiring
  Thank you for the photo of your trailer's European wiring. You will be best served by replacing the Euro style connectors on your trailer to the RV-type. We do not offer Euro style wiring harness kits for vehicles. The part you referenced, adapter # 118710, adapts a European vehicle to a 4-pole type connector but does not adapt the trailer to match U.S. wiring. Euro wiring has every function on a separate wire; while here in the U.S. trailer wiring combines the stop and turn signals. The...
  view full answer...
  
• Troubleshooting Turn Light Fuse Blowing With Cargo Trailer
  If you add additional wire you're still going to be getting under the trailer to run it. I would go ahead and look under the trailer to check for a short in the wiring. Many times this can be found near the lights where the wire connects. It would also be a good idea to check out your connector. Make sure it is free from any debris and corrosion. If you don't find anything, instead of running a separate 4-way I would run new wire from the lights to your 7-way connector. It would also be...
  view full answer...

Do you have a question about this Trailer Wiring?