TM 10-3930-659-20 6-16. LEFT PANEL WIRING HARNESS MAINTENANCE (Con’t). 6. Remove four screws (17), washers (18), and cover (19) from heater housing (16). 7. Disconnect two heater blower diode connectors (20) from heater blower diodes (15). 8. Disconnect two defroster blower diode connectors (22) from defroster blower diodes (21). 6-66