Boost Gauge - Supercharger: Description and Operation

With the ignition switch in the ON or START position, power is supplied
^ through 1O A fuse [No. (10), located in the fuse block (J/B)]
^ to combination meter terminal (29) for meter and gauges.
Ground is supplied
^ to combination meter terminal (13) for gauges and tachometer, and
^ to combination meter terminal (22) for speedometer
^ through body grounds (M3) and (M90).

The boost gauge indicates the turbocharger negative pressure. The reading on the gauge is based on the voltage of the turbocharger boost sensor.
As the pressure of the turbocharger decreases, the voltage of the turbocharger boost sensor decreases. The boost gauge is regulated by a signal
^ from terminals (2) and (3) of the turbocharger boost sensor
^ to combination meter terminals (5) and (11) for the boost gauge.
The boost gauge converts the voltage into the boost pressure displayed.