Lumina L4-151 2.5L (1991)
Fuse: Customer Interest
Background Lights - Inoperative
Number: 93-161-8A
Section: 8A
Date: APRIL 1993
Corporate Bulletin No.: 338103R
ASE No.: A6
Subject:
INOPERATIVE BACKGROUND LIGHTING CUSTOMER COMEBACKS
Model and Year:
1990-93 LUMINA
CONDITION:
There have been some reports that all the background lights on the # 8 circuit may become inoperative on the 1990-93 W-Car. Because this is an
intermittent condition, the headlamp switch may be replaced more than once, resulting in customer comebacks. This bulletin offers a diagnostic
procedure to find the cause of this condition and correct it properly.
The lights on the # 8 circuit include:
-
Cluster Lighting
-
HVAC Controls Lighting
-
Power Door Lock Switches Lighting
-
PRNDL Lighting (with console)
-
Headlamp Switch Lighting
-
Radio Lighting
-
Power Window Switches Lighting
-
Power Mirror Switches Lighting
-
Ash Tray Light
NOTE:
This condition affects only the background lighting portion of the headlamp switch. The headlamps and parking lamps will still operate properly.
CAUSE:
The electronic components in the headlamp switch that control the background lighting may be damaged by an intermittent short circuit before the fuse
blows. If a headlamp switch must be replaced, but only the background lighting circuit is inoperative, the steps listed below should be followed. This is
especially important if the headlamp switch has been replaced before on this vehicle. Section 8A-117 contains the wiring diagram for this circuit.
CORRECTION:
Before installing a new headlamp switch, the wires in the # 8 circuit (gray wires) should be examined for intermittent short circuits. The most likely areas
for these shorts are the floor console wiring, the wiring inside the doors (especially in pass-through areas), and behind the instrument panel.
If a short cannot be located, the following procedure can be used to isolate the area of the short:
1.
Remove the old headlamp switch.
2.
Locate the two gray wires coming from the 106-way connector (C200) near the right hand kickpad. These wires are coming from cavities 2A (door
switches) and 9N (console wires).
3.
Splice and solder a one amp fuse holder into each of the circuits. The fuse holders are available from a local electronics supply outlet, such as
Radio Shack. Their P/N's are: Fuse Holder, 270-1281, and Fuse, 270-1283. Equivalent parts can also be used.
4.
Install a new headlamp switch. Test drive the car to see if the short can be reproduced. If the short does not reoccur, return the car to the customer.
5.
If the vehicle returns with the background lighting out in either the door switches or the console, one of the fuses should be blown. Check that
circuit for an intermittent short to ground, and replace fuse(s).
If the headlamp switch background lighting circuit has failed again, and neither fuse is blown, then check the I.P. wiring for an intermittent short to
ground, and replace the headlamp switch.
