Terminal C inspection

WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Measure the wave pattern of the terminal C on the panel light control switch using an oscilloscope.

Fig 1: Measuring Panel Light Control Switch Wave Pattern - Terminal C
Courtesy of MAZDA MOTORS CORP.
Set the headlight switch to either the TNS or headlight position.
Set the panel light control switch to the brightest position.
Verify that the pattern on the screen is as shown in the figure.

Fig 2: Identifying Wave Pattern On Screen - Brightest Position
Courtesy of MAZDA MOTORS CORP.
Verify that the pattern on the screen matches the pattern shown in the figure as the panel light control switch is gradually turned to the darkest position.

Fig 3: Identifying Wave Pattern On Screen - Darkest Position
Courtesy of MAZDA MOTORS CORP.