Blinker not working

[cwdavis]

To start if there is already a post that will help me please point me to it. As I have not been able to locate one.

What we are working with is. A 71 C10. New wiring harness and the blinkers are LED.

The issue in question is my driver side rear blinker is not working. This is what I have done so far to trouble shoot the issue.

I switched the taillights to make sure it was out the taillight itself.
I tested for power going into and coming out of the connector under the bed and have the correct voltage. I then traced the wire from the connector to the taillight and tested. I have no power.
I checked the ground and it looks good.
I tried using a jumper wire from the connector to the taillight and was getting no power.
I then used a jumper for the ground and still no power.
I then did all this on the working blinker to make sure I should be getting a result.

Any help would be greatly appreciated.