Illumination

Battery voltage is applied to the coil and contact of the tail lamp relay from fusible link F. With the light switch (multifunction switch) in the PARK or HEAD, ground is provided to the tail lamp relay coil through the light switch.
Battery voltage from Left tail lamp fuse is then provided to the illumination lamps through the closed contact of the tail lamp relay. Ground is provided to the illumination lamps through the rheostat. The rheostat controls brightness of the illumination lamp's light.