Red Fuel Select Off Annunciator Comes On During Engine Start And Aural Warning Horns Sound; Red Fuel Select Off And Amber L, R, Or L-R Fuel Low Annunciators Come On; Red Fuel Select Off Annunciator Comes On During Flight And Aural Warning Horn Sounds - Textron Cessna Grand Caravan Ex 208B Pilot's Operating Handbook And Faa Approved Airplane Flight Manual