Primary Brake Warning Indicator Inoperative. Isuzu Isuzu T-Series (Truck Line C) 2002

For 1990-2009 cars only

Makes 🢒 Isuzu 🢒 2002 🢒 Isuzu T-Series (Truck Line C) 🢒 Brakes 🢒 Air Brakes 🢒 Primary Brake Warning Indicator Inoperative

Circuit Description

The PRIMARY BRAKE indicator illuminates when ground is applied to the primary brake indicator control circuit.

Step	Action	Yes	No
Schematic Reference: Brake Warning System Schematics
1	Did you review the Brake Warning System Description and Operation and perform the necessary inspections?	Go to Step 2	Go to Symptoms - Hydraulic Brakes
2	Verify a fault is present. Does the system operate normally?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Is the PPRIMARY BRAKE indicator and the low air pressure warning alarm inoperative?	Go to Step 4	Go to Step 6
4	Disconnect the low air pressure switch. Connect a fused jumper wire from the primary brake lamp control circuit to the ground circuit. Turn ON the ignition. Does the PRIMARY BRAKE indicator illuminate?	Go to Step 12	Go to Step 5
5	Connect the fused jumper wire from the primary brake lamp control circuit to a good ground . Does the PRIMARY BRAKE indicator illuminate?	Go to Step 10	Go to Step 9
6	Disconnect from the instrument panel cluster, the harness connector containing the battery positive voltage circuit. Connect a test lamp from the battery positive voltage circuit to a good ground. Does the test lamp illuminate?	Go to Step 7	Go to Step 11
7	Test the primary brake lamp control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 13	Go to Step 8
8	Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement?	Go to Step 13	--
9	Repair the open in the primary brake lamp control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 13	--
10	Repair the open in the ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 13	--
11	Repair the open in the battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 13	--
12	Replace the low air pressure switch. Refer to Low Air Pressure Switch Replacement . Did you complete the replacement?	Go to Step 13	--
13	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2