Replaced factory cluster w aftermarket. Turn signal issues

When you "change stuff" makes it harder to draw that diagram in the brain, for sure. That is as good a place as any. The thing is, "stuff happens" especially with older girls, that defies logic. "It just might be" that while you were under that dash wiring things up, the ground wire out under the hood finished rusting away LOL

An easy way to start is to figure a way to connect to the front lamp shells if you can access them. string a light wattage test lamp / or your meter from the lamp ground shell to the battery negative. Turn on the park lamps then the turn signals and see if the test lamp shows any color or the meter any voltage "In general" don't discount weird stuff like bulbs screwed up..........such as the filaments inter-connected so that turning on the park lights sends power to one side of the turn signal or vice versa. Stuff "similar."

Another "gotcha" is mis wired, or some odd cross wiring caused by things like abraided harness wires, OR PREVIOUS SHORTS from "melt" damage.

Sometimes, all it takes is one little wandering strand of wire.........you lost track of