FX Series LED Side Steps for GMC Sierra 2500HD Double Cab

Quick answer

Plan the LED wiring before you hang the boards, then install the FX Series side steps bracket-first, snug all hardware, and torque the mounting points last. On the 2007-2018 GMC Sierra 2500HD/3500HD Double Cab, test-fit each side and keep the LED harness clear of pinch welds and moving suspension parts.

Step-by-step FX Series LED side step install

1. 1. Park, chock, and lift safely: Park on level ground, chock the rear wheels, and raise the truck on jack stands so you can work under the rocker panel. Common mistake: working on ramps only, which leaves too little clearance to feed the LED harness along the frame. Confirm the truck is stable before you put any weight on a board.
2. 2. Lay out the hardware and identify each bracket: Unpack the kit and match brackets, bolts, and washers to the positions shown in the supplied instructions. Common mistake: mixing left and right brackets because they look similar; mark them with tape before installation. If the hardware count does not match the instructions, stop and contact the seller.
3. 3. Test-fit the board and plan the LED harness route: Hold the board against the mounting points and trace where the LED harness will run to the cab. Common mistake: routing the harness where it can rub on a pinch weld or contact moving suspension parts; keep it clear and add protection at sharp edges. Leave a small service loop near the board so the harness is not tensioned when the truck flexes.
4. 4. Install the brackets and snug, do not torque: Bolt the brackets to the factory mounting points and tighten them just enough to hold position. Common mistake: fully torquing one bracket before the others are started, which pulls the board out of alignment. All bracket bolts should be snug before any are final-torqued.
5. 5. Set the board position and check clearance: Mount the board to the brackets, set the step height and fore-aft position, and check clearance to the body and to the front and rear tires through their travel. Common mistake: setting the board too close to the rocker panel, which causes contact under load. Open and close both doors fully to confirm no contact.
6. 6. Connect the LED circuit and test before final torque: Connect the LED harness to the power source you planned in step 3, then test every lighting function. Common mistake: finishing the mechanical install and discovering a wiring fault after everything is torqued; test while the hardware is still adjustable. If a function does not work, check the ground and connector before removing the board.
7. 7. Torque all hardware and recheck: Torque the bracket and board fasteners to the values in the supplied instructions, then recheck clearance and LED function. Common mistake: skipping the recheck after torque, which can reveal a shifted board or a pinched harness. Re-torque after the first few hundred miles of driving.

Product facts

• ARMORDILLO® FX SERIES 2007-2018 GMC Sierra 2500HD 3500HD Double Cab Side Steps Running Board w/ LED- Matte Black: Heavy-duty steel construction in a matte black finish with an integrated multifunction LED lighting system. The steel body carries real weight, so use jack stands and a helper rather than holding a board in place by hand.

  

• ARMORDILLO® FX SERIES 2007-2018 GMC Sierra 2500HD 3500HD Double Cab Side Steps Running Board w/ LED- Matte Black: Listed fitment is 2007-2018 GMC Sierra 2500HD/3500HD Double Cab. Check your cab style and year first; a Crew Cab or Sierra 1500 needs a different running board.