Chevrolet SUBURBAN 1993 Owner's Manual page 94

The transfer case shift lever is on the floor to the right of the driver. Use this
lever to shift into and out of four-wheel drive. An indicator near t9e lever
shows you the transfer case settings:
4L
O N
2H
4H
The front axle portion of the indicator diagram will light up when you shift into
four-wheel drive. A slight delay between shifting and the indicator's lighting is
normal. If the indicator does not light up, or if the front axle light does not go
out after you shift out of four-wheel drive, have your dealer check your
system.
When your headlights or parking lights are on, rotate the dial to the right of
your headlight switch to adjust the brightness of your transfer case indicator
light. Rotate the dial up to brighten, or down to dim, the indicator light.
Transfer Case Shift Positions
2H
(High): This setting is for driving in most street and highway situations.
Your front axle is not engaged in two-wheel drive.
4H (High): This setting engages your front axle to help drive your vehicle.
Use 4H when you need extra traction, such as on wet or icy roads, or in
most off -road situations.
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