See what our Experts say about this Pollak Custom Fit Vehicle Wiring

• Troubleshooting No Power To Trailer Brakes When Trailer Connected To New GM Truck
  When you hooked up to the GM trucks, did you notice if the truck said trailer connected? The towing computer on the newer GMC trucks is kind of finicky and if it did not recognize the trailer, or the trailer was not setup in the system it will not send power to the trailer brakes. If you were getting the no trailer connected message you will need to use the 7-Way Trailer Adapter # C57003 which has load resistors and will help the computer detect the trailer. If the trailer was not setup...
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• Solution to Allow Trailer Running Light Circuit to Function on 2019 GMC Sierra 1500
  The trailer wiring on the newer trucks like what you are experiencing on your 2019 GMC Sierra 1500 and the new Ford trucks with the "smart tow" package are proving to be challenging for reasons like what you found where the truck doesn't want to show a trailer connection. The easiest solution you'll have will be the 7-Way Trailer Adapter # C57003 which was designed for German vehicles towing trailers with LED taillights that has load resistors built into it. Basically you'd install this...
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• What is Difference Between Pollak Metal 7-way and Roadmaster
  Hey Rhys, there's basically no difference between the Pollak 7-way part # PK12703 and the Roadmaster part # RM39DQ. If I were you I would go with the one that is priced better.
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• Which Fuse Provides 12-Volts to 7-Way Connector on 2009 Chevy Silverado 3500 Diesel
  If the 12-volt pin on your trailer connector isn't working, you've got a missing or blown fuse or the wiring connection at the fuse box under the hood wasn't finalized. You're looking for a 40 amp fuse, located in position # 68 in the fuse box under the hood. The fuse protects one of the nearby power studs on the side of the fuse box, which is where the wire that provides power to the 7-way should be connected. If it's not, you can find the wire bundled up under the master cylinder (see...
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• 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 top and rotating 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 Yellow and Left Turn...
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• Difference Between 7-Way Wiring Diagram that Uses Red Wire and Purple Wire
  There are actually two ways that 7-way wiring colors are commonly seen. One uses a red wire and the other a purple. The circuits they represent do vary though. So check out the updated diagram I attached to this page and most likely you need to wire the connector up like the center one.
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• Trailer Running Lights Do Not Work but Brake Lights and Turn Signals Do Work
  It could be a tow package fuse on the vehicle. Use the owners manual to find the locations of fuses/relays related to the tow package wiring to check them and replace as needed. If the issue is not a fuse or relay then you can test the vehicle side trailer connector using a circuit tester such as # PTW2993. Turn the vehicle headlights on and use the circuit tester to test the pins on the connector at the back. If there is no power on the running light pin then there is a break or loose...
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• Troubleshooting Trailer Running Lamp Circuit on 2020 Chevy 1500
  GM refers to that circuit as the 'Trailer parking lamp'. The fuse is in location # 41 in the fuse box in the engine compartment. After replacing the fuse, you'll want to closely examine the running lamp circuit on your trailer. You'll want to locate and repair the short that caused the fuse to blow, before plugging the trailer in for the first time. Otherwise, you'll continue to blow fuses. I'll link to a troubleshooting article that you might find helpful.
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• Troubleshooting Trailer Lights That Don't Work With Power Flowing to It
  Hey Ray, this sort of thing happens quite a bit actually. Usually what's happened is that there is either a short in the circuit, or there's an issue with the ground. I'd recommend checking the grounds and make sure they are connected securely, and attached to a clean bare metal surface. You'll also want to make sure there is no dirt, corrosion or debris on the connectors as that could also be causing your issue. Next, If the grounds and connectors look good, I'd check the wiring and...
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• Troubleshooting No Power on the Blue Brake Output Wire from a Brake Controller
  To determine why you do not have any power on the blue brake output wire, I recommend starting at your brake controller. First, make sure the brake controller is on and receiving power. Most brake controllers have 4 wires, blue (brake output to trailer brakes), white (ground), black (12 Volt power from vehicle battery), and red (stop light switch). If your brake controller is not on, make sure the black power wire is connected to the vehicle battery via a 20 or 30 amp circuit breaker....
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• Metal 6-Way and 7-Way Replacement for Older Ford Truck
  Email me back with the pictures and I'll see if we can help.
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• My 2024 GMC 3500HD just had the Module Replaced and Won't Detect Trailer, and No Running Lights
  Hello Trent, Since your other lights are working on the trailer but your running lights are not, have you tried to turn your headlights on? I know in my 2024 Chevy Silverado I have to have the headlights on in order for the running lights on my Ranger boat trailer to turn on. If your 2024 GMC HD3500 is powering the trailer lights but not recognizing that a trailer is connected, it usually comes down to how the truck detects the trailer. Instead of just sensing that something is plugged...
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• Troubleshooting Running Lights On Enclosed Trailer That Only Work Sometimes
  Hello Isaiah. There are a few things that could be causing this. The first thing I would check are the pins on your trailer connector, and on the vehicles connector. Rust or corrosion on these pins can cause certain lights to work while others don't. Clean up or replace the connector on both sides as needed. Another thing to do is check your ground. A bad ground can cause all kinds of lighting issues, and this is quite frequently the cause of similar issues. If all of that checks out, I...
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• Troubleshooting A Non-Working Running Light On A Boat Trailer
  Hey Paul, Stop/turn signal light functions typically use the same wire and the running lights are on their own. You'll want to go to the passenger side and check the running light wire for power with a multimeter # PT89ZR. If you aren't receiving power at the light then you'll trace that wire back to the power source looking for damage and checking for power until you find where it stops. With this being a boat trailer I would typically just rip out the old wiring and start with new...
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• Why Won't Trailer Lights Work When Running Lights are On
  Hey Malachi, what you described does sound like an insufficient ground even though you did say you checked all of them. I would try running a ground circuit back from each light all the way back to the main ground of the trailer wiring and see if that fixes the issue. Let me know if that helps.
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• What Could Cause Brake Controller To Have Low Voltage Output?
  Hello Ed, thanks for reaching out. Brake controllers can show a low voltage on a circuit tester if the output setting of the brake controller is on the lower side. So make sure yours is set all the way up to make sure what you are testing for should be the full brightness on the tester. In general though if you have a brake controller that will only put out a low voltage it's probably got an internal issue and would need to be replaced.
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• Troubleshooting Loss Of Brake Controller Output
  Hey Dave, A short in your brake controller output wire would definitely cause issues with your brake controller functionality and prevent the signal from reaching the brake assemblies. What brand and model brake controller do you have? Are you seeing any output at the 7-way when pressing the manual override?
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• Left Turn Signal Works on a 1996 Ford F-350 But There is No Power at the Trailer Plug
  The first step to troubleshooting your issue would be to eliminate any obvious causes. First, check your trailer connector for dirt or corrosion. Dirt and corrosion can prevent a signal from reaching the pin on the connector. If you see corrosion on the exterior of the connector, then it may be possible that the corrosion or dirt and penetrated deeper into the connector. I would recommend replacing the trailer connector if this is the case. Be sure you test each pin on the trailer connector...
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• 7-Pole To 4-Pole Trailer Connector Adapter To Flat Tow 1997 Suzuki Sidekick
  From your photos you have a 7-blade connector on the RexAir and a 4 pin round connector on the 1997 Suzuki Sidekick. The blue wire in your photos is a 4 pin to 4 pin connector which will not work to connect the RV and the Suzuki. All you need is a 7-pole to 4-pole adapter part # HM47043 to connect the RV to the Suzuki.
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• How to Make the 12 Volt Accessory Circuit Active on a 2004 Chevy Silverado 7-Way
  Yes, there is a connection that will need to be made for the 12 volt accessory circuit of the 7-way on your 2004 Chevy Silverado active. This is the circuit that will power the cargo lights on your trailer. Check out the FAQ article I attached that details what you will need to do. Step F deals specifically with the connections and fuses that are needed for the 12 volt circuit.
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• Troubleshooting No Power from the Blue Brake Controller Wire
  Yes, and no proportional brake controllers will not engage the brakes with the pedal unless the tow vehicle is in motion. You would need to use your manual override button if you want to check the brakes while sitting idle. A proportional controller, which is the most common type, senses the motion of the vehicle, and applies the brakes with the same degree of force that the vehicle is slowing down. If you're getting power to the trailer brakes using a battery then the issue is either...
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• What Can Be Used To Test Your Trailer Connectors For Functionality
  Hi Ken, You can use a test light # PTW2993, multimeter # PT89ZR, 7-Way to RV Socket LED Circuit Tester # C73NR, 4-pole light tester # F4CT, or any other type of tester that can read DC voltage to test your 4-pole or 7-way socket.
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• Troubleshooting Running Lights Flicker When Braking and Hitting Bumps
  Hi Christopher; have you checked your ground connections? That may have been auto correct when you said "backgrounds" but it could be a loose ground and the braking/bumps are enough that it is moving it around causing the running lights to flicker. Since you can't find anything else in the trailer wiring I would look at the vehicle. You can check out your vehicle connector and inspect the wiring but it will be really hard to use a tester to see if the vehicle is the issue since it requires...
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• Troubleshooting Non-Working Running Lights On A 2013 Jayco Jay Flight Swift SLX 184BH
  Hi Jose, If you had a short in the wire it's highly likely that you just blew the fuse for the running light circuit and need to replace the fuse in your tow vehicle. Worst case scenario you could also have burned up the wire or damaged the lights and would need to replace them all as well, but I doubt that's the case. I would start by checking the 7-way to see if each light function is coming through. If not check the trailer specific fuses for your vehicle and replace as needed. Once...
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