My 99 Beettle have a problem, The hot red light turns on and off, I changed the radiator,the fans, the water pump and still doing it. What could that be?:mad:

My 99 Beettle have a problem, The hot red light turns on and off, I changed the radiator,the fans, the water pump and still doing it. What could that be?:mad:
Try a new thermostat and also a new coolant temp sensor.

if that doesnt get it, it might just be the coolant level sensor in the coolant reservoir. to test to see if thats it, unplug the connector that plugs into your coolant reservoir when the red light is flashing, and jump the 2 terminals on the connector with a paper clip and see if the light goes off. if it does, then its a bad coolant level sensor and you need a new reservoir.