Kerwin, need some answers first. Then we will get it fixed. Unless you already have it fixed.
1. Is your turn signal a clamp-on aftermarket switch (part no.? and brand?) or a GM accessory switch which is part of the column "bell"?
2. Does the turn signal switch have 6 wires going into it?
3. Describe what happens when switch lever is push down for left turn. Describe what happens when left lifted up for right turn. What do front and rear light do or not do?
4. Do brake lights work properly? Do tail lights come on with headlights?
5. Were all lights and turn signals and brake lights working and this just happened? If not, explain history of this issue.
Please don't guess on any of this or use previous observations, please test again. Describe carefully.
The directional switch wiring is very simple.
Get an ice pick style voltage tester. Forget the multimeter. After questions answered, we will see if it's all wired correctly using the ice pick tester. Then begin to identify the problem. One step at a time. So far sounds like a bad bulb or bad ground somewhere. Not a wiring problem. Not sure yet. Wire colors is not a good way to describe wires at this point. The to-from routing explanation is better.
