I just installed the Cab Clearance Marker lights on my truck today! it looks great! start to finish took 2.5-3 hrs. I purchased the following parts from Ford
1 - GC3Z*15A404*S Wiring Harness (you will need to verify that that harness is for your truck, apparantly there are different ones for different trucks)
5 - 6C3Z*15442* A Lights
10 - N621903*S441 Nuts
I pulled the headliner down about 6" and then disconnected the Air bags and XM Raido plugs and pulled out the wiring harness from the roof, then unplugged it from under the dash and tied a string around the plug and pulled it out the driver side pillar and tied a string onto the new one and pulled it back in and got everything reconnected. then marked the roofs center line in line with the rear view mirror and also I measured from each side of the truck to find center for sure. then measure 5 3/4" from where the rubber gasket meets the windshield and that is my center X. from that point go the standard 13----8---0---8----13. I used a sharp step bit and drilled 3 holes for each light (2 for the bolts and 1 for center wire plug. the center hole is going to be pretty large about 7/8". after all the holes are drilled it's easy, paint the bare metal on the sides of the holes you drilled to help prevent rust, then install the lights plug them in and test and put the headliner back and you are done!
My truck has a moonroof which made the install much easier, if you don't have a moon roof I think you may have to remove the headliner all the way or at least drop it down a lot more then I had to.
hope this helps someone, if I can answer any questions let me know.
1 - GC3Z*15A404*S Wiring Harness (you will need to verify that that harness is for your truck, apparantly there are different ones for different trucks)
5 - 6C3Z*15442* A Lights
10 - N621903*S441 Nuts
I pulled the headliner down about 6" and then disconnected the Air bags and XM Raido plugs and pulled out the wiring harness from the roof, then unplugged it from under the dash and tied a string around the plug and pulled it out the driver side pillar and tied a string onto the new one and pulled it back in and got everything reconnected. then marked the roofs center line in line with the rear view mirror and also I measured from each side of the truck to find center for sure. then measure 5 3/4" from where the rubber gasket meets the windshield and that is my center X. from that point go the standard 13----8---0---8----13. I used a sharp step bit and drilled 3 holes for each light (2 for the bolts and 1 for center wire plug. the center hole is going to be pretty large about 7/8". after all the holes are drilled it's easy, paint the bare metal on the sides of the holes you drilled to help prevent rust, then install the lights plug them in and test and put the headliner back and you are done!
My truck has a moonroof which made the install much easier, if you don't have a moon roof I think you may have to remove the headliner all the way or at least drop it down a lot more then I had to.
hope this helps someone, if I can answer any questions let me know.