Installation Instructions for GMC Full-Size Van

Part Numbers:

• 41946

Wiring Access Location:

• SUV3, SUV4

Tools Required:

• Wrenches: 13/16", 15/16"
• Drill Bits: 9/16"

Step-by-Step Instructions:

1. Enlarge Frame Holes:

   • Enlarge existing holes in the frame to 9/16" at eight locations.

2. Insert Fasteners:

   • Insert bolts, brackets, and spacer blocks through the existing access slots and into the attachment holes on each side of the frame.

3. Position Hitch:

   • Raise the hitch into position and align it with the attachment holes.

4. Secure Hitch:

   • Fasten the hitch using flat washers, lock washers, and nuts as shown in the diagram.

5. Tighten Fasteners:

   • Use a torque wrench to tighten all 9/16"-12 fasteners to 110 lb-ft (149 N*m).

Torque Specifications:

• 9/16"-12 GR5 bolts: 110 lb-ft (149 N*m)

Hardware List:

• (10) Hex Bolts, 9/16"-12 x 1.75" GR5
• (10) Lock Washers, 9/16"
• (14) Flat Washers, 9/16"
• (10) Hex Nuts, 9/16"-12
• (2) Spacer Blocks, 3/8" x 1-1/2" x 3"
• (2) Spacer Blocks, 1/4" x 1-1/2" x 2"
• (1) Left-Hand Bracket
• (1) Right-Hand Bracket

Safety Notes:

• Check the hitch frequently to ensure all fasteners and the ball are securely tightened.
• If the hitch is removed, plug all holes in the trunk pan or other body panels to prevent water or exhaust fumes from entering.
• Replace any damaged hitch or ball immediately.
• Always wear eye protection and observe safety precautions when working beneath the vehicle.
• Do not cut access or attachment holes with a torch.

Specifications:

• Weight Carrying (Ball Mount):
  • Max Gross Trailer Weight: 10,000 lb (4,540 kg)
  • Max Tongue Weight: 1,500 lb (681 kg)
• Weight Distributing:
  • Max Gross Trailer Weight: 13,000 lb (5,902 kg)
  • Max Tongue Weight: 1,300 lb (590 kg)

Additional Notes:

• This product complies with V.E.S.C. Regulation V-5 and SAE J684 safety standards.
• Ensure proper alignment and torque specifications to maintain safety and performance.

Installation Instructions for T-Connector Adapter

Part Numbers:

• 118377

Wiring Access Location:

• Near the rear interior trim panels close to the doors.

Tools Required:

• Screw or cable ties (provided).

Step-by-Step Instructions:

1. Remove the rear interior trim panels near the doors.

   • Locate the vehicle’s tail light wiring harness. Connection points will be present on both sides of the vehicle, matching the ends of the T-Connector adapter.

2. Disconnect the vehicle’s wiring harness connectors on the driver’s side.

   • Caution: Be careful not to damage the locking tabs.

3. Position the black box on the left (driver’s) side of the vehicle.

   • Plug the T-Connector harness containing the yellow wire into the left vehicle wiring harness connector.
   • Ensure the connectors are fully inserted and secured using the existing and provided locking tabs.

4. Repeat the procedure for the passenger side using the connector containing the green wire.

5. Route the green wire under the floor trim (threshold) panel.

   • Secure the black box to the vehicle using the provided screw or cable tie behind the driver’s side trim panel.

6. Reinstall the rear trim panels removed in step 1.

7. Test the installation with a test light or trailer.

   • Specifications:
     • This unit is rated for 7.5 amps per circuit.

Hardware List:

• T-Connector adapter.
• Black box.
• Cable ties or screws.

Safety Notes:

• On some early production vehicles, the tail light and stoplight circuits may be reversed. If this condition is present, wires can be switched according to the included diagram or by consulting a dealer.
• Ensure all connections are clean and securely fastened.
• Test the installation after completing all steps to verify functionality.

Manufacturer Notes:

• Follow all warnings and instructions provided with the product.
• Use a test light or trailer to confirm proper installation.

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:

1. 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.

2. 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.

3. 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.

4. 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).

5. 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:

1. 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.

2. 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).

3. 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).

4. 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.

5. Reconnect the Battery:

   • Reattach the negative battery cable and ensure all connections are secure.
   • Insert the fuses into both circuit breakers.

6. Secure All Wires:

   • Use cable ties to secure all loose wires and prevent damage or rattling.

7. 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.