Are side marker lamps suppose to blink???

Diagrams for how to make side markers blink can be found at Daniel Stern lighting website. Here's the key though. Your side marker fixtures will need isolated bulb sockets and a ground wire ( 2 wires, 1 filiment ) a metal chassis ground bulb socket wont work.
I made the little round side marker lights on a 68 fish blink with the turn signals by changing there bulb sockets.