Temperature signal and temperature gauge on 1998 Volkswagen Cabrio

The (red) signal is flashing intermittently, but the gauge says my motor is just at normal temperature, what's wrong you think?

Asked by for the 1998 Volkswagen Cabrio
Check the coolant level, make sure it's right. If you accelerate hard while the engine is cold the light will flash also.

I appreciate this answer, I will look on for the coolant level. Could it be that the signal is defective too? Can this little red flashing (annoying) heating signal be defective too?
My car is doing this same thing! I've noticed it especially does it after my car has been parked in the sun for many hours. My coolant level is fine, so it's got to be something else. I had a Honda before my vw ad if it was parked in the sun for many hours it would simply not start. At least my vw is starting I suppose, but I would love to have a fix to this.