Side marker "lenses", what's the deal?

[dmjlambert]

Originally Posted by Gmc.guy

My 69 has the same front reflectors. Were the rear/red lenses the same, just reflector? My bedsides were pretty wasted in that area. Wife harness was too rough to give clues too I am far from that on the truck still. This thread made me think of it again

Yes, the front and back reflectors were the same type, just amber in the front and red in the back. So it looks like mine was made just before the lighting requirement.

Besides the reflector itself not having the bulb holder, my wiring harness does not put wires for adding a bulb near that hole on any of the 4 corners of the truck. I am not clear what sort of lighting goes there, if it is supposed to be just running lights or turn signal too.