For 2003‑2024 Chevy Express 3500 Trailer Wiring 7 Way Trailer Wiring Plug w/ Bracket Fits All Models Curt
Model: 55540 57672 51500 58361-CW387This Wiring 7-Way + Bracket Fits The Following Vehicles:
2003 - 2024 Chevrolet Express 3500 All Models
This Wiring 7-Way + Bracket Includes the Following Parts:
- Custom Wiring, 4-Flat (Plug & Play)
- Dual-Output Electrical Adapter (Adds 7-Way RV Blade to 4-Way Flat)
- Trailer Brake Controller Wiring Kit (duplex undercar wires, circuit breakers, terminals & ring connectors)
- 30-Amp Universal Circuit Breaker
- Installation instructions, schematics, diagrams, and hardware (if required).
List of Fitment Years:
2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024
CURT 55540 Vehicle-Side Custom 4-Pin Trailer Wiring Harness
Manufactured by: Curt
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution A custom wiring harness -- also called a T-connector -- is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation.
Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Chevy Express and GMC Savana 1500, 2500, 3500 and 4500 (to verify your vehicle compatibility, see application info) It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use.
You have a picture in mind of your next destination -- maybe it's the boat landing at your favorite fishing spot, maybe it's a campsite that overlooks one of nature's masterpieces, or maybe it's the next big jobsite However, turning that picture into a reality takes more than just daydreaming It takes a solid connection and the right amount of power.
CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup..
Features:
- Plugs into vehicle tail light assembly to provide a 4-way flat socket
- Simple plug-and-play design eliminates the need for cutting or splicing
- 4-way flat output connects tail lights, brake lights and turn signals
- Dust cover included to keep connector clean when not in use
- Backed by a limited one-year warranty
CURT 57672 Dual-Output 4-Way Flat Vehicle-Side to 7-Way RV Blade Trailer Wiring Adapter
Manufactured by: Curt
There are several different types of connectors used to supply power from a tow vehicle's electrical system to a trailer's wiring system Some trailers only need the bare essentials -- running lights, brake lights and turn signals -- while others require a connection for reverse lights, electric brakes and auxiliary power With connectors ranging from simple to complex, it may be the case that the connection between your vehicle and your trailer is not a perfect match.
For example, your truck may be equipped with a 6-way round socket, but your trailer may have a 4-way flat plug For this very common problem, CURT offers a quick and simple solution in the form of an electrical adapter An adapter is an electrical device that allows a connection to be made between a mismatched trailer plug and vehicle socket.
It easily plugs in your vehicle's electrical socket and usually requires no additional wiring CURT offers an array of adapters to accommodate most types of plugs and sockets, including 4-way flat, 4-way round, 5-way flat, 6-way round, 7-way RV blades and more This special dual-output electrical adapter is actually designed to adapt a 4-way flat vehicle socket to fit multiple trailer plugs, including a 4-way flat and a 7-way RV blade connector.
Some manual wiring is required This multipurpose socket also comes with dust covers, a mounting bracket and all necessary mounting hardware for a complete installation All CURT wiring and electrical products come with a one-year limited warranty to give you the assurance you need to tow with confidence..
Features:
- Adapts a 4-way flat socket to fit 4-way flat and 7-way RV blade trailer plugs
- 4-way flat output connects tail lights, brake lights and turn signals
- 7-way connects tail, brake, reverse, turn signals, brakes and auxiliary power
- Dust covers included to keep connectors clean when not in use
- Slit loom keeps wires contained and well protected
- Metal bracket securely mounts wiring to the vehicle or trailer hitch
CURT 51500 Electric Trailer Brake Controller Wiring Kit
Manufactured by: Curt
It takes a lot of power to stop a moving trailer, especially when that trailer is hauling livestock, construction materials, industrial equipment or other heavy-duty cargo Play it safe when you tow and give your trailer brakes the control they need with a CURT trailer brake controller and brake controller harness This brake controller wiring kit is designed for vehicles that do not have an included towing prep package.
It includes cables, ring terminals, cable ties and a circuit breaker to splice into your vehicle's wiring system and allow installation of a CURT trailer brake controller This wiring kit is compatible with systems with up to eight brakes..
Features:
- For tow vehicles not equipped with factory tow package wiring
- Compatible with 2, 4, 6 or 8-brake systems (1-4 axles)
- Designed for use with CURT quick plugs #51515 or #51516
- Brake controller and trailer connector are not included
CURT 58361 30-Amp Universal Circuit Breaker
Manufactured by: Curt
Whether you're a contractor on your way to the jobsite or just a casual fisherman heading to the boat landing, you need working trailer lights to tow safely and legally For any towing setup, CURT offers quality wiring components, including complete wiring kits, circuit breakers, wiring connectors and more This universal circuit breaker is rated for 30 amps and recommended for applications where over-current protection is required..
Features:
- Recommended for applications where over-current protection is required
Hitches Near Me: We operate out of several warehouses across the country, ensuring faster delivery to your location.
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Product Details
- Brand: Curt
- Model: 55540 57672 51500 58361-CW387
- Includes: Custom Wiring, Dual-Output Electrical Adapter, Trailer Brake Controller Wiring Kit, 30-Amp Universal Circuit Breaker
Compatibility Chart
Description
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For 2003-2024 Chevy Express 3500 Trailer Wiring 7 Way Trailer Wiring Plug w/ Bracket Fits All Models Curt Install Notes
Installation Instructions for Chevrolet Express and GMC Savana
Part Number:
- 55540
Tools Required:
- Ratchet
- 10mm socket
Step-by-Step Instructions:
-
Disconnect the Battery:
- Locate the vehicle battery on the driver's side under the hood.
- Disconnect the negative battery terminal to ensure safety during installation.
-
Remove Rear Trim Panels:
- At the rear entry doors, remove the rear trim fascia and any interior trim panels, if equipped, to access the taillight wiring harness.
-
Access Taillight Wiring Harness:
- Locate the vehicle's taillight wiring harness connectors behind the driver-side rear access panel (S3) and passenger-side rear access panel (S4).
- These connectors will resemble those on the custom wiring harness.
- Carefully separate the connectors from the taillight housing, ensuring not to damage the locking tabs.
-
Install the Custom Wiring Harness (Driver's Side):
- Insert the custom wiring harness end with the yellow wire between the separated connectors on the driver's side.
- Ensure the connectors are fully inserted with locking tabs in place.
-
Establish Ground Connection:
- Locate a suitable grounding point near the connector, such as an existing screw with a nut in the vehicle frame.
- If no suitable point is available, drill a 3/32" pilot hole for the provided screw.
- Ensure the grounding area is free of rust, dirt, and paint.
- Secure the white ground wire using the ring terminal and provided screw.
Warning: Before drilling, check for any items that may be hidden behind or under any surface to avoid damage and/or personal injury.
-
Install the Custom Wiring Harness (Passenger's Side):
- Route the custom wiring harness end with the green wire to the passenger side behind the removed trim panels.
- Sufficient wire length is provided to route under the threshold plate or above the rear cargo doors.
- Repeat the connection process on the passenger side using the harness end with the green wire.
-
Secure Wiring and Reassemble Trim Panels:
- Tuck the green wire under the floor trim panel to keep it secure and out of sight.
- Reinstall all previously removed rear trim panels and ensure they are properly secured.
-
Reconnect the Battery:
- Reconnect the negative battery terminal to restore power to the vehicle's electrical system.
- Install the provided 4-flat dust cover to help prevent corrosion on the connectors.
Safety Notes:
- Warning: Do not exceed the product rating or the tow vehicle lamp load rating, whichever is lower. Exceeding the product rating can cause loss of warranty, overheating, and potential fire.
Note: After installation, test the wiring harness for proper function by using a test light or connecting a properly wired trailer.
Installation Instructions for Chevrolet Express and GMC Savana
Part Number:
- 55540
Tools Required:
- Ratchet
- 10mm socket
Step-by-Step Instructions:
-
Disconnect the Battery:
- Locate the vehicle battery on the driver's side under the hood.
- Disconnect the negative battery terminal to ensure safety during installation.
-
Remove Rear Trim Panels:
- At the rear entry doors, remove the rear trim fascia and any interior trim panels, if equipped, to access the taillight wiring harness.
-
Access Taillight Wiring Harness:
- Locate the vehicle's taillight wiring harness connectors behind the driver-side rear access panel (S3) and passenger-side rear access panel (S4).
- These connectors will resemble those on the custom wiring harness.
- Carefully separate the connectors from the taillight housing, ensuring not to damage the locking tabs.
-
Install the Custom Wiring Harness (Driver's Side):
- Insert the custom wiring harness end with the yellow wire between the separated connectors on the driver's side.
- Ensure the connectors are fully inserted with locking tabs in place.
-
Establish Ground Connection:
- Locate a suitable grounding point near the connector, such as an existing screw with a nut in the vehicle frame.
- If no suitable point is available, drill a 3/32" pilot hole for the provided screw.
- Ensure the grounding area is free of rust, dirt, and paint.
- Secure the white ground wire using the ring terminal and provided screw.
Warning: Before drilling, check for any items that may be hidden behind or under any surface to avoid damage and/or personal injury.
-
Install the Custom Wiring Harness (Passenger's Side):
- Route the custom wiring harness end with the green wire to the passenger side behind the removed trim panels.
- Sufficient wire length is provided to route under the threshold plate or above the rear cargo doors.
- Repeat the connection process on the passenger side using the harness end with the green wire.
-
Secure Wiring and Reassemble Trim Panels:
- Tuck the green wire under the floor trim panel to keep it secure and out of sight.
- Reinstall all previously removed rear trim panels and ensure they are properly secured.
-
Reconnect the Battery:
- Reconnect the negative battery terminal to restore power to the vehicle's electrical system.
- Install the provided 4-flat dust cover to help prevent corrosion on the connectors.
Safety Notes:
- Warning: Do not exceed the product rating or the tow vehicle lamp load rating, whichever is lower. Exceeding the product rating can cause loss of warranty, overheating, and potential fire.
Note: After installation, test the wiring harness for proper function by using a test light or connecting a properly wired trailer.
Warranty:
For complete warranty information, please download the full installation PDF.
Technical Support:
For technical support and assistance, our team of experts is available to help. You can reach our tech support by visiting www.trailerjacks.com or calling 877-869-6690.
Installation Instructions for 4-Way to 7-Way Adapter and Brake Control Wiring
Tools Required:
- Phillips Head Screwdriver
- Drill with 3/32" Drill Bit
- 10mm Socket & Ratchet or Wrench
- Wire Crimpers
- Wire Cutters
- Test Light or Multimeter
- Cable Ties
Part 1: Install the 4-Way to 7-Way Adapter
Step-by-Step Instructions:
-
Mount the Adapter:
- Choose a suitable mounting point on the vehicle, typically near the hitch.
- Use the provided bracket and screws to secure the adapter.
-
Connect the 4-Flat Plug:
- Plug the 4-flat connector on the adapter into the existing 4-flat plug on the vehicle.
- This connection enables tail lights, left turn, and right turn signals.
-
Ground the Adapter:
- Locate a clean, solid grounding point near the adapter.
- Drill a 3/32" hole if necessary and secure the white ground wire from the adapter using the provided screw and eyelet.
-
Leave Additional Wires Disconnected:
- The following wires will remain disconnected until Part 2:
- Black Wire: Power from the battery.
- Blue Wire: Brake control output.
- Yellow Wire: Reverse light (optional; leave disconnected unless needed).
- The following wires will remain disconnected until Part 2:
-
Test Initial Connection:
- Use a test light or trailer to verify functionality of the 4-way connections (tail lights, turn signals).
Part 2: Install Brake Control Wiring
Step-by-Step Instructions:
-
Mount Circuit Breakers:
- Install two 30A circuit breakers on the firewall or another suitable location near the battery.
- Use self-tapping screws to mount them securely.
-
Route Power Wires:
- Connect the black 12-gauge wire from the 7-way adapter to the auxiliary side of one circuit breaker (this powers the 7-way socket).
- Run a heavy-gauge wire from the battery's positive terminal to the battery side of this circuit breaker, using a ring terminal.
- Run another heavy-gauge wire from the battery's positive terminal to the auxiliary side of the second circuit breaker (for the brake controller).
-
Install the Brake Controller:
- Mount the brake controller under the dash on a firm surface.
- Use the following connections:
- Red Wire: Connect to the cold side of the brake switch (active only when the brake pedal is pressed).
- Blue Wire: Connect to the blue wire on the 7-way adapter for trailer brakes.
- White Wire: Connect to a solid ground point on the vehicle body.
- Black Wire: Connect to the auxiliary side of the second 30A circuit breaker (provides power to the brake controller).
-
Optional: Connect Reverse Light Circuit:
- If the trailer has a reverse light circuit, connect the yellow wire from the 7-way adapter to the vehicle’s reverse light circuit.
-
Reconnect the Battery:
- Reattach the negative battery cable and ensure all connections are secure.
- Insert the fuses into both circuit breakers.
-
Secure All Wires:
- Use cable ties to secure all loose wires and prevent damage or rattling.
-
Test the System:
- Verify functionality of all circuits (running lights, turn signals, brake lights, and brake controller output).
- If applicable, test the reverse light circuit.
Notes:
- Most installations will only require connecting the black and blue wires from the 7-way adapter.
- Leave the yellow wire disconnected unless the trailer has a reverse light or surge brake lockout circuit.
- Always adhere to safety guidelines and verify all connections before use.
Warning: Incorrect wiring can cause damage to the vehicle or trailer. Test all connections carefully before use.
Installation Instructions for 4-Way to 7-Way Adapter and Brake Control Wiring
Tools Required:
- Phillips Head Screwdriver
- Drill with 3/32" Drill Bit
- 10mm Socket & Ratchet or Wrench
- Wire Crimpers
- Wire Cutters
- Test Light or Multimeter
- Cable Ties
Part 1: Install the 4-Way to 7-Way Adapter
Step-by-Step Instructions:
-
Mount the Adapter:
- Choose a suitable mounting point on the vehicle, typically near the hitch.
- Use the provided bracket and screws to secure the adapter.
-
Connect the 4-Flat Plug:
- Plug the 4-flat connector on the adapter into the existing 4-flat plug on the vehicle.
- This connection enables tail lights, left turn, and right turn signals.
-
Ground the Adapter:
- Locate a clean, solid grounding point near the adapter.
- Drill a 3/32" hole if necessary and secure the white ground wire from the adapter using the provided screw and eyelet.
-
Leave Additional Wires Disconnected:
- The following wires will remain disconnected until Part 2:
- Black Wire: Power from the battery.
- Blue Wire: Brake control output.
- Yellow Wire: Reverse light (optional; leave disconnected unless needed).
- The following wires will remain disconnected until Part 2:
-
Test Initial Connection:
- Use a test light or trailer to verify functionality of the 4-way connections (tail lights, turn signals).
Part 2: Install Brake Control Wiring
Step-by-Step Instructions:
-
Mount Circuit Breakers:
- Install two 30A circuit breakers on the firewall or another suitable location near the battery.
- Use self-tapping screws to mount them securely.
-
Route Power Wires:
- Connect the black 12-gauge wire from the 7-way adapter to the auxiliary side of one circuit breaker (this powers the 7-way socket).
- Run a heavy-gauge wire from the battery's positive terminal to the battery side of this circuit breaker, using a ring terminal.
- Run another heavy-gauge wire from the battery's positive terminal to the auxiliary side of the second circuit breaker (for the brake controller).
-
Install the Brake Controller:
- Mount the brake controller under the dash on a firm surface.
- Use the following connections:
- Red Wire: Connect to the cold side of the brake switch (active only when the brake pedal is pressed).
- Blue Wire: Connect to the blue wire on the 7-way adapter for trailer brakes.
- White Wire: Connect to a solid ground point on the vehicle body.
- Black Wire: Connect to the auxiliary side of the second 30A circuit breaker (provides power to the brake controller).
-
Optional: Connect Reverse Light Circuit:
- If the trailer has a reverse light circuit, connect the yellow wire from the 7-way adapter to the vehicle’s reverse light circuit.
-
Reconnect the Battery:
- Reattach the negative battery cable and ensure all connections are secure.
- Insert the fuses into both circuit breakers.
-
Secure All Wires:
- Use cable ties to secure all loose wires and prevent damage or rattling.
-
Test the System:
- Verify functionality of all circuits (running lights, turn signals, brake lights, and brake controller output).
- If applicable, test the reverse light circuit.
Notes:
- Most installations will only require connecting the black and blue wires from the 7-way adapter.
- Leave the yellow wire disconnected unless the trailer has a reverse light or surge brake lockout circuit.
- Always adhere to safety guidelines and verify all connections before use.
Warning: Incorrect wiring can cause damage to the vehicle or trailer. Test all connections carefully before use.
Attention:
This is a summary of the installation procedure. For complete installation instructions, including diagrams and detailed information from the manufacturer, please download the full installation PDF.
Warranty Information:
For complete warranty instructions, please download the full installation PDF.
Technical Support:
For technical support and assistance, our team of experts is available to help. You can reach our tech support by visiting www.trailerjacks.com or calling 877-869-6690.
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