I agree with
goodwrench1984 on the most likely problems. Intermittent on and then off or partial lighting could be anything from the IPC itself, the central power supply or the body control module, with the central power supply being prone to temperature related issues, and all parts having cold solder joint problems as possible cause. Check your trouble codes by entering the diagnostics to see what codes are stored. If you don't know how to do this, I or others here can help with that. If you find the problem and need a replacement part, I may have it.