The needle on temperature gauge rattles after the car warms up - at least that is when I notice it the most. I can tell that while driving and hit a bump, I get the erratic reading. I was wondering if anyone in the community has any suggestions on where to start looking.

Wire from the sender to plug in shelf has a high joint (going open under the sheath). Take a VOM and check for continuity.

This is your second electrical problem post in short (no pun intended) order.

Not that I have a bunch of expertise, but maybe checking some grounds would cure more than one issue? It seems like a common answer.