S10/T10 Blazer 4WD V6-262 4.3L VIN Z (1994)
Four Wheel Drive Indicator Lamp: Initial Inspection and Diagnostic Overview
Circuit Operation - Four-Wheel Drive Indicator
The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is
supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector
Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps.
With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit.
With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and
the Indicator Assembly Front and Rear Axle Display is lit.
With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the
Indicator Assembly Front and Rear Axle Display is lit.
A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent
operation during 4WD operation.
Preliminary Checks - Four-Wheel Drive Indicator
1. Check condition of IGN/GAU Fuse. If fuse is Blown, locate and repair overload. Replace fuse.
2. If fuse is not blown, proceed with the Diagnostics. See: Symptom Related Diagnostic Procedures
