Here's some info from the service
CD: (need to check 9 fuses!)
The instrument panel dimmer switch sends a signal to the
instrument cluster which then sends a backlighting intensity and dimming curve command over the standard corporate protocol (SCP) link to the
front electronic module (
FEM), the audio unit, and the dual automatic temperature control (
DATC) module. The
FEM then sends a pulse width modulated (PWM) dimming signal to the
instrument cluster, the dimmable LEDs, and the dimmable incandescents.
Fault Management
The dimmable backlighting will default to 100% intensity if an instrument panel dimmer switch failure occurs.
Inspection and Verification
Binding or damaged instrument panel dimmer switch
Central junction box (CJB) fuse(s)
13 (5A)
20 (10A)
30 (5A)
33 (10A)
Rear battery junction box (BJB) fuse(s)
10 (30A)
14 (30A)
23 (5A)
31 (30A)
41 (15A)
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Ron
VIN #7729, seq.#7505, blue premium,
partial blue interior, no top, Louisville Ky.