temp gauge goes down to nothing

ASSISTANCE Electrical & Entertainment Systems
1

When car is at regular operating temperature, whenever i go more than 3/4 throttle, the temp gauge drops down past the C until i let off the throttle and then it will jump back up to where it’s supposed to be within a couple seconds.

Any ideas why this would happen?

Thanks

2

Check the ground to the cluster, [black] the temp, fuel and tach. gauges share a common ground.:cross:94