I got the fog lights installed this weekend. It took a couple hours to install the brackets, wiring harness, switch and lights. Then I had to take it to Freightliner to have them program the smart switch. They're working like a charm.
First, I installed the switch in the dash. To do this you must remove the dash frame and panel, remove the knob from the air brake actuator and unplug the switches. Then you can take the aluminum panel to your workbench and add a rectangular whole for the Fog Light switch.
Second, you find an available smart switch connector in the dash. Mine were tucked up to the left of the left-center air vent. You can get easier access by unscrewing the instrument cluster and sitting it on the dash.
Third, plug all the switch back in and re-install the instrument panel, switch panel, air brake actuator know and dash frame.
You're done in the cab.
Fourth, you install brackets and lights in the bumper. You'll re-use one bolt, one nut and one washer on the left and right sides as the brackets share holes with the bumper facia. So it's BOYB (Bring Your Own Bolts) and nuts and washers for the other two. There are already holes in the bumper for the brackets...so there is no drilling. Yay!!
Fifth, you mount the lights.
Sixth, you route the harness to the lights from the split in the harness...just follow the existing harnesses.
Seventh, you attach the ground wire to ground point on the frame. It's easy to see sticking out. Don't forget to sand off the paint before attaching it and then spray over it when you're done.
Eighth, you then route the rest of the harness to the Chassis Module under the cab on the driver's side...look to the left of the cab batteries above the fuel tank. The module is mounted to the bottom of the cab. You'll unplug the 16-pin connector (marked C3). Remove the two plug in the holes and add the two wires for the positive wires to locations C and D on the connector. While looking at the connector from the wired side locations C and D are the 3rd and 4th position up from the bottom on the right side.
Reinstall the connector and you're done.
Now the smart switch needs to be programmed. That will cost you $100 bucks, but it's all warrantied and Freightliner OEM.