DTC P1663: Generator Light Control Circuit (3.8L "G" Body): Notes
WARNING: This page does not describe the selected car, but rather 65 other vehicles, including the 1999 Saturn SW2, 1999 Saturn SW1, 1999 Saturn SL2, 1999 Saturn SL1, and 1999 Saturn SL. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For circuit reference, see appropriate wiring diagram in WIRING DIAGRAMS article.