Justin, I did a quick reply but did not see it hit the forum. If this is a duplicate, just ignore.
I've got the same turn signal kit to install on my 48 Chevy. To summarize all the posts, it looks like the new turn signal yellow and green wires are routed to one of the original signal filament bulbs, correct? Therefore, the stop light and tail light wires go to the new dual filament bulb, correct? Finally, where did you attach the fused red wire in the kit that attaches to one terminal on the flasher? I tried wiring mine directly to the battery and that does not appear to work. Also, did it make a difference whether you had the switch mounted to finaly get the turn signals to work? (I figured it shouldn't since there was already a dedicated ground connection from the switch.) Thanks for any advice; hopefully I can learn something from your pain.