Diagnosis And Testing

Check the ignition fuse in the Power Distribution Center (PDC). Repair as necessary.
Using a scan tool, check for any Diagnostic Trouble Codes (DTCs) related to the vacuum cleaner system. If any DTCs are found, repair as necessary.
Check the vehicles battery open-circuit voltage and charging system performance. If the vehicle's electrical system is defective or weak it may not be supplying sufficient energy to operate the vacuum cleaner system.
If there are no DTCs and the vacuum cleaner system powers on and functions properly, but the switch indicator does not illuminate, the switch may need to be replaced.