1996 GMC Sonoma Owner's Manual - Page 69

The front axle portion of the diagram on the indicator will light up when you shift into four-wheel drive. A slight delay between shifting and the pattern's lighting is normal. If the pattern does not light up, or if the front axle lights do not go out after you shift out of four-wheel drive, have your dealer check your system. Turn the INT LIGHTS switch located to the right of your headlamp switch to dim your transfer case indicator light when your headlamps or parking lamps are on. This will also cause your instrument panel lights to dim. 2H1: This setting is for driving in most street and highway situations. Your front axle is not engaged in two-wheel drive. An indicator light near the lever shows you the transfer case settings: 0 2HI 4HI 4HI: This setting engages your front axle to help drive your vehicle. Use 4HI when you need extra traction, such as on snowy or icy roads, or in most off-road situations. N SET PARK BRAKE: Shift to this neutral setting only when your vehicle needs to be towed. N SET PARK BRAKE 4LO 2-21