90 Quattro 20V L5-2309cc 2.3L DOHC (7A) (1990)
Backup Lamp Switch: Locations
Back-Up Light Switch (Manual Transmission)
Back-Up Light Switch (Manual Transmission)
Switch should be closed (completing the circuit) only when Reverse gear is engaged.
NOTE: On 1991-1992 cars with 4-speed automatic transmission, power to the back-up lights is controlled by the automatic transmission relay. See
Four-speed Automatic Transmission.