Inspection Procedures

SYMPTOM PROCEDURES

Malfunction of the ignition switch power supply system

Ignition Switch Power Supply Circuit:

TECHNICAL DESCRIPTION (COMMENT)
When the power supply system of ignition switch has a problem, none of the equipment and system connected to the ignition switch works even if the ignition switch is operated.

TROUBLESHOOTING HINTS
- Malfunction of the ignition switch
- Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:
- MB992006: Extra fine probe
- MB991223: Harness set

STEP 1. Check ignition switch connector C-308 for loose, corroded or damaged terminals, or terminals pushed back in the connector.







Q: Is ignition switch connector C-308 in good condition?

YES : Go to Step 2.

NO : Repair the defective connector.

STEP 2. Check the battery power supply circuit to the ignition switch. Measure the voltage at ignition switch connector C-308.

1. Disconnect the connector, and measure at the wiring harness side.










2. Measure the voltage between terminal 1 and ground.
- The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES : Go to Step 4.

NO : Go to Step 3.

STEP 3. Check the Wiring harness between ignition switch connector C-308 (terminal No.1) and fusible link (4).







NOTE: Prior to the wiring harness inspection, check intermediate connector C-24, and repair if necessary.

- Check the battery power supply line for open circuit.

Q: Is the check result normal?

YES : Go to Step 5.

NO : Repair the wiring harness.

STEP 4. Check the ignition switch.

Remove the ignition switch. Then check continuity between the switch terminal.







Q: Is the ignition switch in good condition?

YES : Go to Step 5.

NO : Replace the ignition switch.

STEP 5. Retest the system.

Q: When the ignition switch is operated, do the equipment and system work normally?

YES : The trouble can be an intermittent malfunction.

NO : Return to Step 1.