Transmission Shift Position Indicator Lamp: Description and Operation

With the ignition switch in ON (II) or START (III), voltage is applied to the A/T gear position indicator. The A/T gear position switch provides a ground for each position. As an input is grounded, its indicator lights up. If you select R, for example, ground will be applied to the input of the A/T gear position indicator, and the R indicator bulb will come on.

With the headlight switch in PARK or HEAD, voltage is applied to the RED/BLK wire terminal. This changes the indicator panel illumination from fixed to controlled by the dash lights dimmer input on the RED wire.