The interior lamps system consists of 2 main features. Illuminated entry and a battery saver feature that will turn the interior lights off after 20 minutes if they are left On with all doors closed and the ignition Off. The body control module (BCM) controls both of these functions. Battery power is supplied by the BCM through CKT 1732 to the following lamps:
• The dome lamp
• The map lamps
• The rear reading lamps
• The rear dome lamp
• The cargo lamp
• The glove compartment lamp
• The courtesy lamps
• The sunshade lamps
The BCM also controls the ground circuit side of the dome lamp and reading lamps for illuminated entry. The dome lamp and reading lamp will remain on for 20 seconds after the ignition key is removed and the last door is closed. In addition, if the vehicle is equipped with remote keyless entry (RKE), the dome and reading lamps will turn On and stay on for 20 seconds after an UNLOCK signal is received from the keyless entry transmitter.
The reading lamps, dome lamp and map lamps can be turned On at any time by moving the appropriate switch to the On position.
The rear dome lamp is fed battery voltage through CKT 1732 from the BCM, through the liftgate ajar switch, and is grounded through CKT 650 to the rear ground splice pack. The rear dome lamp will turn on when the liftgate is opened. The cargo lamp is fed battery voltage through CKT 1732 from the BCM, through CKT 744 and grounded through the decklid ajar switch.
The courtesy lamps are fed battery power through CKT 1732 and are grounded through CKT 745-- left front, CKT 747--left rear, CKT 748--right rear, CKT 746--right front. These circuits will ground through the door jamb switches. The courtesy lamp will be illuminated when the affected door is opened. For example, when the right rear door is opened, the right rear door courtesy lamp will turn on.
Not a fuse problem , if the BCM had blown fuse other thing's wouldn't be working as well . . Probably wiring or BCM . Using factory diagnostic,s instead of guessing as to what the problem is , is the proper way .
Interior Lamps Diagnosis
Important: Before proceeding with these diagnostics, check for DTCs. If DTCs are present, complete the associated diagnostics. If the condition still exists, return to this chart.
All of the interior lamps are inoperative when any door is opened.
The dome lamp is inoperative in the ON position, but OK in the door position. The map lamps operate normally.
The dome lamp switch is faulty. Replace the dome lamp switch.
The dome lamp is inoperative in the DOOR position, but is OK in the ON position.
The dome lamp is inoperative in any position and both reading lamps are inoperative.
Disconnect the dome lamp connector (BLK 3-way).
Check for voltage at terminal "C" CKT 1732 ORN wire.
If OK, the dome/map lamp is faulty. If no voltage is present, there is an OPEN in CKT 1732.
Either the right or the left sunshade mirror lamp is inoperative.
Either the right or the left rear reading lamp is inoperative in the ON or the DOOR position.
The rear reading lamp is inoperative in the ON or the DOOR position.
Battery rundown protection is shorted to ground - B1482.
The left rear reading lamp is inoperative in the ON or the DOOR position.
1998 Saturn SL
on Dec 12, 2017