How To Install Cab Marker Lights

Article written by catmechanic07.

This should work on any model of Ford pickup truck. Some may vary a little due to year model's, overhead consoles and such. This is an article on installing cab marker lights, sometimes also called clearance lights.

These are the tools I used to do this:

• 3/8" drill (air or electric)
• 1" hole saw bit
• 1/8" drill bit (for pilot holes)
• 3/8" drill bit
• 1/4" ratchet
• 1/4" extension (6 inch length worked good)
• 1/4" 10mm deep weld socket
• 1/4" 7 or 8 mm socket
• Phillips screw driver
• Flat blade screw driver
• Torx bit set (socket type or screw driver type)
• wire ties (small ones)
• wire cutters
• wire stripper
• wire crimper
• electrical test light
• a sharpie marker (whatever color stands out so you can see it against your paint)

OK! I took my lights apart and set the bases on the cab so they looked like the F-350's do. I kinda "eyeballed" them for where they should be sitting. Then I took each one and marked both sides and front and back with the sharpie. I only put a dot for a locator mark to go back to. Then I marked my holes for the hold downs and the power plug to go thru.

Then the real fun starts. Take the sun visors off and small supports for them also. If you have a center overhead console remove it also. The front piece you have to unplug the wire for the light. Then take the plugs off the side posts to access the two 7 or 8mm bolts holding those on. Remove the bolts (i didnt take the post covers all the way out, just let them hang in there) Then take the 2 screws out of the overhead console at the front of the rails. There should be a black mounting plate that slides up in the rails. Pull that out and you should have access to see the roof in behind the liner. To get the black mount out you will have to pull the liner down a little to clear it.

Now take the 1/8" drill bit and drill pilot holes for your mounting bolts to go thru (2 for each light base) and the power plug holes also (1 each base). Once thats done, take the 3/8" bit and drill the holes that size for the mounting bolts. (depending on the bases.....the bit size may be smaller) While using the 3/8" bit, drill the power plug holes that size also. Once you get that done, take the 1" hole saw and use the 3/8" holes as a pilot for the bit on it and drill out the center holes. ( The metal will get hot, try to keep it off the liner foam or it may do damage. I kept a magnet under mine to catch it).

Now clean around the area where your lights will mount. Take the bases and apply a VERY thin coat of silicone to where they will touch the cab. They should come with a foam piece to seal them but I still put silicone on them. Put the bases thru the holes and put the nuts on the under side under the head liner. Once all are tight and secure. Go back and clean any silicone they may have squeezed out. ( I used black silicone since the bases were black).

Now take the wiring harness and plug into the farthest one towards the drivers side. Thats the way they run from the factory. I took and cut my wires and ran the ground to the post where the grab handle is using one of the bolts to hold it. Then ran the power wire to my headlight switch. You may want to find a hot wire in the fuse box and a good ground and try them now to make sure they work correctly.

Then put your truck back together the way it came apart. The side posts are a little tricky getting them lined back up and keeping them under the trim all at the same time. Once its back together, pop the headlight switch panel cover out. Use a test light to find the power wire to the park lights. I used a special wire end to go into that prong so my lights came on with the park lights. Last thing, put the covers on the bases. You should have a nice looking set of marker lights now. If you have any questions anyone can send me a private message.