Section 531 (Instrument Cluster): Tachometer: Description
A tachometer is standard equipment on all instrument clusters. The tachometer is located next to the speedometer, just to the right of center in the instrument cluster. The tachometer consists of a movable gauge needle or pointer controlled by the instrument cluster circuitry and a fixed 255 degree scale on the gauge dial face that reads left-to-right from "0" to "7" for gasoline engines. On vehicles with a diesel engine, the scale reads from "0" to "5". The text "RPM X 1000" imprinted on the cluster overlay directly above the hub of the tachometer needle identifies that each number on the tachometer scale is to be multiplied by 1000 RPM. See Fig 1.
The tachometer text is white against a black field, while the major and minor scale increments are black against a silver field. A light gray inner secondary scale provides a balanced appearance between the tachometer and speedometer, but is purely cosmetic. All text and increments are clearly visible within the instrument cluster in daylight. The gasoline engine tachometer has red increments designating the engine red line beginning at 5800 RPM, while the red increments for the diesel engine tachometer begin at 4000 RPM. When illuminated from behind by the panel lamps dimmer controlled cluster illumination lighting with the exterior lamps turned On, all text and major increments appear blue-green, while the red major increments still appear red. The minor increments and the secondary scale are not illuminated. The red gauge needle is internally illuminated.
Gauge illumination is provided by replaceable incandescent bulb and bulb holder units located on the instrument cluster electronic circuit board. The tachometer is serviced as a unit with the instrument cluster.