Chart B Telltale Lamp Does Not Come "On"

CIRCUIT DESCRIPTION
When the ignition switch is first turned "On," system voltage is applied from the "IGN 1" fuse to "WLAMPHI," Terminal "B9," and to the "Air Bag" telltale lamp which is connected to "WLAMPLO," Terminal "A1." The "Air Bag" fuse applies system voltage to the "IGN 1" inputs, Terminals "A3" and "B3." The DERM resp9nds by flashing the "Air Bag" telltale lamp seven times.

When the engine is being cranked, system voltage is applied from the "IGN 3" fuse to the DERM at the "Crank" input. The DERM responds by grounding the "WLAMPLO" output until system voltage is removed from the "Crank" input. This results in the "Air Bag" telltale lamp being "On" during cranking.

After cranking the DERM will again flash the "Air Bag" telltale lamp seven times.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks whether the fault is in the instrument cluster and wiring.
2. This test checks whether the fault is in the power feed to the instrument cluster.
3. This test checks for an open in the "WLAMPLO" circuit.
4. This test checks for a short from the "WLAMPLO" circuit to B+.
5. This test checks for a good ground to the DERM. Check Circuits 1003E and 1003C or 152H and 152J at I/P chassis ground. If the ground is good the fault is a faulty DERM.
6. This test checks whether the fault is due to a bad fuse.
7. This test checks whether a circuitry fault opened the fuse.
8. This test checks whether the circuitry fault is internal to the DERM.
9. This test checks whether the fault is due to a bad bulb.
10. This test checks for an open in the "WLAMPHI" circuit and the instrument cluster power feed circuit.
11. This test determines whether the open is in the "WLAMPLO" circuit or the instrument cluster printed circuit.