GM Astro/Safari 1985-1996 Repair Guide

Dimmer Switch


When servicing any components on the steering column, should any fasteners require replacement, be sure to use only nuts and bolts of the same size and grade as the original fasteners. Using screws that are too long could prevent the column from collapsing during a collision.


Except 1996 Models

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: A drill bit should be used to limit switch travel and aid in dimmer switch adjustment

  1. If equipped, properly disable the SIR (air bag) system. For details on disabling the air bag system, please refer to Chassis Electrical of this information.
  3. Disconnect the negative battery cable.
  5. If equipped, remove the lower column trim panel.
  7. Remove the steering column-to-instrument panel fasteners and lower the column for access to the switch. Extreme care is necessary to prevent damage to the collapsible column.
  9. On some vehicles it may be necessary to remove the steering wheel in order to fully lower the column. If equipped with a tilt column, position the column in the upper most position for additional lowering clearance.

If the ignition switch shares fasteners with the dimmer switch it may be necessary to remove it first.

  1. Remove the dimmer switch-to-steering column retainers, then remove the switch from the column. Disengage the switch wiring and remove it.

To install:
  1. Position the switch to the column and loosely install the retainers.
  3. Insert a 3 / 32 in. drill bit into the adjustment hole provided in the switch in order to limit switch travel, then push the switch up against the actuator rod in order to remove lash.
  5. Tighten the switch retainers, then remove the drill bit.
  7. Engage the switch wiring.
  9. If removed for access, install the ignition switch.
  11. Raise the column into position and secure, then install any necessary trim plates.
  13. If removed install the steering wheel.
  15. Make sure the ignition is OFF , then connect the negative battery cable.
  17. If equipped, properly enable the SIR system.

1996 Models

Instead of the long time used steering column found on most older GM vehicles the 1996 Astro and Safari vans are equipped with a new column that uses a multi-function combination switch mounted at the head of the column (below the steering wheel) and an upper/lower shroud assembly. The combination switch performs such functions as the wiper switch and the turn signal switch along with any other duties of the multi-function lever. For removal or installation of the multi-function switch assembly, please refer to the Combination Switch procedure found in this section.