Courtesy Light

[Rrod]

Dome light not working with dash dimmer switch. Light works when either door is opened. What wire from dash dimmer supplies ground to dome light when switch is turned to courtesy light position?

[pschlosser]

The dimmer switch, when it's turned all the way to the detent (not sure which direction) should illuminate the light.  The yellow wire coming from the dimmer switch should be going to ground when illumination is activated.

[Cuda Cody]

You can remove the switch and check it outside the car.

[Rrod]

How do you bench test the courtesy light function of the dash dimmer?

[shawge]

The dimmer switch can be part of the path to ground along with the door switches (yellow wires).
When at detent, D(ome) terminal should have continuity with the switch body, and eventually to body ground.

May have some corrosion at terminal rivet to copper spring or copper spring to switch body.

Things to check for dimmer ground path:
- Terminal rivet to copper spring continuity when detent pushes them together
  - Ensure clean metal and solid contact
    In attached pics, you can see the terminal rivet is dirty
    There was no continuity across terminal and copper spring when detent closed
- Copper spring to switch body
  - This area is often corroded on spring side (green circles)
  - Make sure tabs hold back of switch tight to body
- Switch body to panel ground (metal bracket switch is attached to)
- Panel ground to dash frame (red circle)
- Dash frame to body


From Slotts:

The 2947713 E body dash dimmer switch will control dimming of the gauges, heater control panel, radio, console and ash tray lights connected to the orange wire E2 circuit output side of the fuse block.

The D R I stamped on the metal switch frame label the Dome, Resistance and Input connections.

The D terminal two yellow wires are from the left and right door switch ground or ground from the switch itself. The dome light always has power at the bulb, grounding completes the circuit from either of these three locations.

The R terminal tan wire is the dimmed output feeding the input fuse block terminal from the resistor.

The I terminal solid black wire is the power feed from the headlight switch parking light output. The black with yellow tracer wire from the I terminal continues on to the headlight warning buzzer connector and drives the key in ignition relay buzzer, if the diode adapter is plugged in.