Before You Get Started...

Warm surfaces and 3M tape with heat gun if ambient temperature is below 68 degrees F

Any Modification or unintended use will void the manufacturers warranty

A dry fit of all pieces must be performed before the final installation of the product to ensure fit

Products cannot be returned for a full refund after the red backing to the 3M tape is removed

Please follow the installation instructions laid out in this video to attach your rear cab spoiler.  If you purchased a version WITH INTEGRATED LIGHTS, skip the video for now and proceed below the video to the Wiring Instructions.

Wiring Instructions

Please note these overlays are sent with two different styles of light. 

• Amber surface mount pill style lights
• Back-side mounted HG2 emergency lights/ SWJS205

​Please reference your part to see which version of the wiring instructions will coincide with the lightsrear roof cap spoiler you received. Scroll down until you find the appropriate instructions.

HG2 Back-Side Mounted Emergency/Chase Lights/Flashers

SURFACE MOUNT "PILL STYLE" CHASE LIGHTS/FLASHERS

The following guide is intended solely as an example of a typical installation and does not constitute a complete technical manual. Customers should alter these steps as necessary to fit their specific vehicle, equipment, and preferences. You may alter the method based on your use case, provided the basic information for the function of the lights is adhered to on the HG2 DS1 (double stack configuration) below, or the the SWJS205 instructions.

SURFACE MOUNT "PILL STYLE" CHASE LIGHTS/FLASHERS

1. Required Tools & MaterialsPlease Note: This kit does not include wiring, fuses, or switches. These items must be purchased separately.
Tools RequiredWire Strippers & Crimpers: For cutting wire and securing electrical connections.
Digital Multimeter or Test Light: To identify and verify 12V power sources.
Heat Gun: For sealing heat-shrink connectors. This is especially important for wiring routed underneath the vehicle.
Zip Ties—Heavy Duty: Use these to secure the wiring underneath the chassis.
Socket Wrench Set: For disconnecting and reconnecting the vehicle battery.
Drill & Stepped Drill Bit: Required when installing aftermarket switches.
Materials Needed—Purchase SeparatelyBecause the wiring must run from the rear of the cab to the switch location, significantly more wire is required than for front-mounted accessories.
Primary Wire—Rear-to-Front RunsMain Power (+12V): Approximately 30 ft of 16 AWG red primary wire.
Pattern Select: Approximately 30 ft of 18 AWG yellow primary wire.
Ground WireChassis Ground: Approximately 5–8 ft of 16 AWG black primary wire. The lights will typically be grounded to the vehicle frame underneath the rear of the cab.
Internal Spoiler WireSynchronization/Pattern Select Jumper: Approximately 4 ft of 18 AWG yellow wire, as needed. This joins the yellow wires from both lights together inside the spoiler and connects them to the long yellow pattern-select wire.
Fuses & Holders

• 1 in-line fuse holder
• 1 5A fuse

Switches

• 1 toggle or rocker switch—ON/OFF—for main power
• 1 normally open momentary push-button switch—for pattern selection

2. Step-by-Step InstallationPhase 1: Bench Assembly—Wiring the SpoilerPerform these steps with the spoiler placed on a stable workbench. Do not mount the spoiler to the truck yet.
Install the LightsSecure both warning lights into the spoiler housing.

• Driver-side light = Light 1
• Passenger-side light = Light 2

These lights do not require a separate master/slave wiring configuration.
Connect the Internal WiresMain PowerConnect the RED wire from Light 1 to the RED wire from Light 2.
Attach the long 16 AWG red main-power wire to this connection. This wire will run forward to the output side of the main power switch.
GroundConnect the BLACK wire from Light 1 to the BLACK wire from Light 2.
Attach the black chassis-ground wire to this connection.
Pattern Select and SynchronizationConnect the YELLOW wire from Light 1 directly to the YELLOW wire from Light 2.
Attach the long 18 AWG yellow pattern-select wire to this same connection.
The yellow wires remain permanently connected together. This allows both lights to remain synchronized and change flash patterns at the same time.
White WiresThe WHITE wires are not used in this installation.
Cap and insulate each white wire separately. Do not connect the two white wires together.
Create the HarnessBundle the long red and yellow wires together using split wire loom or high-quality electrical tape.
Route the black ground wire separately as needed for the planned chassis-ground location.
Make sure the harness exits the side of the spoiler overlay through the intended wire-routing location.

Phase 2: Harness Routing—The Under-Cab RunPosition the Spoiler TemporarilyPlace the spoiler on the rear roof without removing the adhesive backing. Use this position to verify the required wire length and routing.
Route Through the Window ChannelRoute the wiring harness out of the side of the spoiler and neatly down the rear cab-window channel between the glass and the cab pillar.
Route Under the CabPull the red and yellow wires down between the cab and truck bed until they reach the underside of the vehicle.
Run the Harness ForwardRoute the red and yellow wires along the frame rail toward the front of the truck and the planned switch location.
IMPORTANT: Secure the wire harness with heavy-duty zip ties approximately every 12 inches.
WARNING: Keep the wiring away from:

• Exhaust components and other heat sources
• Suspension components
• Steering components
• Sharp metal edges
• Moving parts

Follow existing factory wiring harnesses wherever practical.
Connect the GroundLocate a clean, secure chassis-ground point underneath the rear of the cab or near the rear frame.
Connect the black ground wire to an existing chassis bolt or approved grounding location.
Remove paint, rust, dirt, and corrosion from the contact area to ensure a clean metal-to-metal connection. Protect the completed connection against moisture and corrosion.

Phase 3: Cab and Switch ConnectionsDisconnect the BatteryDisconnect the negative battery terminal before making the final power and switch connections.
Route the WiresPull the red and yellow wires into the engine bay.
Route the necessary switch wires through an existing firewall grommet and into the dashboard or switch-panel area.
Do not drill through the firewall unless necessary. Avoid damaging factory wiring located behind the drilling area.
Connect the Main Power SwitchThe main power circuit should be connected in the following order:
Battery positive → 5A fuse → main power switch → red wire leading to both lights

1. Connect a fused 12V positive power source to the input terminal of the main ON/OFF switch.
2. Install the 5A fuse as close to the power source as practical.
3. Connect the output terminal of the main switch to the long red wire leading to the lights.

The main switch output becomes the switched +12V power source for the system.
Connect the Momentary Pattern SwitchUse a normally open momentary push-button switch.

1. Connect one terminal of the momentary switch to the switched +12V output of the main power switch.
2. Connect the other terminal of the momentary switch to the long yellow wire leading to the joined yellow wires on both lights.

The pattern switch must be connected after the main power switch. This ensures the pattern-selection circuit only receives power while the light system is turned on.
When the momentary button is pressed, it temporarily applies switched +12V power to the joined yellow wires.
Do not use an ON/OFF toggle switch for the yellow pattern-select circuit. The yellow wire must not remain continuously connected to positive power.

Phase 4: System TestTest the entire system before removing the spoiler’s adhesive backing or completing the final mounting.
Reconnect the BatteryReconnect the vehicle battery after verifying that all wiring is properly insulated and secured.
Test Main PowerTurn the main power switch on.
Both lights should begin flashing in their currently stored flash pattern.
Test SynchronizationConfirm that both lights flash together in the same pattern.
If the lights are not synchronized, verify that:

• Both yellow wires are permanently connected together.
• Both lights are receiving the same switched +12V power.
• Both black wires have a secure chassis ground.

Test the Pattern ButtonPress and release the momentary push button.
Both lights should advance to the next flash pattern simultaneously.
Continue pressing and releasing the button until the desired pattern is selected.
Reset to Pattern 1To reset both lights to Pattern 1, press and hold the momentary button for approximately five seconds, then release it.
Confirm the White WiresVerify that both white wires remain separately capped and insulated.
The white-wire asynchronous function is not used in this installation.

Phase 5: Final MountingAfter confirming that the lights operate correctly:

1. Inspect all electrical connections.
2. Confirm that all heat-shrink connectors are fully sealed.
3. Secure all wiring away from heat, sharp edges, and moving components.
4. Confirm that the spoiler harness has enough slack to prevent tension on the light connections.
5. Return to the top of the installation page and follow the included installation video to complete the spoiler mounting process.

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HG2 Back-Side Mounted Emergency Lights/Flashers/Chase 

​1. Required Tools & Materials
Please Note: This kit does not include wiring, fuses, or switches. You must purchase these separately.
Tools Required

• Wire Strippers & Crimpers: For cutting and securing wire connections.
• Digital Multimeter or Test Light: To verify 12V power sources.
• Heat Gun: For sealing heat-shrink connectors (Crucial for under-vehicle wiring).
• Zip Ties (Heavy Duty): You will need plenty of these to secure the wire run underneath the chassis.
• Socket Wrench Set: For battery disconnection.
• Drill & Stepped Drill Bit: Required if you are installing aftermarket switches.

Materials Needed (Purchase Separately) Because the wiring must run the full length of the truck cab, significantly more wire is required than for front-mounted accessories.

• Primary Wire (Main Runs - Rear to Front):
  • Main Power (+12V): ~30 ft of 16 AWG (Red).
  • Takedown Signal: ~30 ft of 18 AWG (Blue).
  • Pattern Select Signal: ~30 ft of 18 AWG (White).
• Ground Wire:
  • Chassis Ground: ~5-8 ft of 16 AWG (Black). You will likely ground this to the frame underneath the rear of the cab.
• Internal Spoiler Wire:
  • Synchronization (Jumper): ~4 ft of 18 AWG (Yellow). Connects the two lights inside the spoiler.
• Fuses & Holders:
  • 1x In-line Fuse Holder with 5A Fuse.
• Switches:
  • 1x Toggle/Rocker Switch (On/Off) – For Main Power.
  • 1x Toggle/Rocker Switch (On/Off) – For Takedowns.
  • 1x Momentary Push-Button Switch – For Pattern Select.

2. Step-by-Step Installation
Phase 1: Bench Assembly (Wiring the Spoiler)Perform these steps with the spoiler placed on a stable workbench. Do not mount it to the truck yet.

1. Install Lights: Secure the two HG2 Flashers into the spoiler housing.
2. Configure Master/Slave:
   • Driver Side Light = MASTER.
   • Passenger Side Light = SLAVE.
3. Connect Internal Wires:
   • Synchronization: Connect the YELLOW wire from the Driver side light directly to the YELLOW wire from the Passenger side light. This wire stays in the spoiler assembly.
   • Takedowns: Connect the BLUE wires from both lights together. Attach your long (30 ft) Blue signal wire here.
   • Main Power: Connect the RED wires from both lights together. Attach your long (30 ft) Red power wire here.
   • Ground: Connect the BLACK wires from both lights together. Attach your Black ground wire here.
   • Pattern Select: Connect your long (30 ft) White signal wire to the WHITE wire of the Driver Side light (Master). Cap off the white wire on the Passenger side; it is not used.
4. Create the Harness: Bundle the long wires (Red, Blue, White, Black) together. Wrap them efficiently in wire loom or high-quality electrical tape. Ensure the harness exits the side of the spoiler overlay as designed.

Phase 2: Harness Routing (The "Under-Cab" Run)

1. Position Temporarily: Place the spoiler on the rear roof to gauge the wire length.
2. Window Channel: Route the wire harness out of the side of the spoiler and tuck it neatly down the channel of the back cab window (between the glass and the pillar/cab).
3. Under the Cab: Pull the harness down between the cab and the truck bed to reach the underside of the vehicle.
4. Run to Engine Bay: Route the wire harness along the frame rail towards the front engine bay.
   • IMPORTANT: Use heavy-duty zip ties to secure the wire every 12 inches.
   • WARNING: Keep the wire far away from the exhaust system (heat) and suspension components (movement). Follow existing factory wiring harnesses where possible.
5. Grounding: Find a clean chassis bolt on the frame (under the cab or near the rear). Secure your BLACK ground wire here. Ensure you scrape away paint/rust for a metal-to-metal connection.

Phase 3: Cab & Switch Connections

1. Enter the Engine Bay: Pull the Red, Blue, and White wires up into the engine bay.
2. Enter the Cab: Route the Blue and White signal wires through the firewall firewall grommet into the dashboard area.
3. Connect Switches:
   • Main Power Switch: Connect the Red wire (via the 5A Fuse) to your Main Power switch source.
   • Takedown Switch: Connect the Blue wire to the Output of your Takedown switch.
   • Momentary Button: Connect the White wire to the Output of your Momentary Pattern switch.

Phase 4: System Test
​Test the system BEFORE peeling the adhesive tape or bolting the spoiler down.

1. Reconnect the battery.
2. Power On: Flip the Main Power switch.
   • Driver Side should flash 2 times (Master).
   • Passenger Side should flash 1 time (Slave).
3. Check Sync: Press the Momentary Button in the cab. Confirm both rear lights change patterns simultaneously.
4. Check Takedowns: Flip the Takedown switch. Both lights should turn solid white.

Phase 5: Final Mounting

1. Please return to the top of this page and follow the installation video included there.