Not sure what relay it is, but mine makes the exact same noise as shown in the other thread, particularly when I have the turn signal on.
As I have read through this thread, I am reading many things and thinking about some current behavior on my truck.
1) I occasionally get the clicking under...
Your are getting a low voltage from your alternator.
I have a UltraGauge so I monitor my voltage. Occasionally if I'm sitting at a stop light with my turn signal on, I'll start to feel the clicking and vibration through the steering wheel. I'll check.and the alternator will be charging at...