I got my side markers from NOPI.com for ~$23 plus shipping. The labor is not too bad, it just involves a lot of careful measurements.
Materials Needed: Marker, Side Marker Lenses, Bulbs, Ruler, Drill, large enough drill bit to make the hole for the lenses, small enough drill bit to make pilot holes for the screws to hold the lenses on, at least 10' of 16 guage wire, solder & soldering iron (can use connectors if solder is not available, touch-up paint, and electrical tape.
The first thing I did was to run the wire. I spliced into the turn signals on each side in the front. Then I ran the wires through the engine compartment and over to each fender.
Next I placed the gasket from the lens against the fender to use it as a placement guide. Once I got the desired position on one side, I traced the holes with the marker and measured its position with a ruler so I could repeat it on the other side.
Then out comes the drill. Take the large bit (in my case this was 1/2") and drill out the hole for the side marker to fit into. After the initial drill, check to see if the lens will fit into the fender. If it does not fit totally flush with the fender, the you must make adjustments to the hole. After that hole is complete, drill the pilot holes that will hold the lens to the fender. Make sure that these are lined up correctly before drilling. Repeat for the other side. Once all holes are drilled, use touch-up paint on the exposed metal surfaces to keep rust from forming.
Now you are ready to connect everything. Finish running the wire through the fender. You can run it along the fender (inside the engine compartment) and into the fender where the door meets the fender. Use a coat hanger (or something similar) to feed the wire to the hole that you drilled. Make sure that the gasket is on the side marker before connecting. Now, solder the wires you ran and the side marker wires together(solder is preferred, but connectors can be used). Wrap the connection in electrical tape. (You may then melt the tape with a soldering iron if desired...I do because it seals the connection better from corrosion.) Now place the side marker in the hole, and screw in the screws that hold the lens on, pop the lens cover on and repeat for the other side.
There, that wasn't too hard...
Back to Modifications