problem with reversing parking sensors

Hi everyone, has anyone had trouble with reversing parking sensors. I have checked the bulbs and checked the wireing and connections on the light cluster, it will work for a few days then it will stop working. Any advice appreciated. 

Bulbs on parking sensors? Are you referring to connection to reversing light cluster for power to sensor control box? Check the earth connection as well.

cheers for that will try it. I checked reversing light bulb in light cluster.