How to Test the Ignition Switch When the Patrol Fails to Start?
3 Answers
Turn the ignition switch to the "OFF" position. Use a Phillips screwdriver to remove the top and bottom fixing screws of the ignition switch, then use a plastic pry tool to open the ignition switch and release the clips. In the "OFF" position, all terminals should be in an open circuit state, and the conductivity between terminals should be infinite. In the "ACC" position, terminals 1-3 should be conductive. In the "ON" position, terminals 1-2-3 and 5-6 should be conductive. Turn the key to the "ST" position, at which point terminals 1-2 and 4-5-6 should be conductive.
When encountering a situation where the Patrol won't start, I usually begin by checking if the ignition switch is functioning properly. Here are the specific diagnostic steps: Ensure the ignition key is inserted and turned to the START position. If the dashboard lights up normally but you don't hear the starter motor turning, it might indicate an ignition switch signal issue. Use a multimeter to test the voltage at the ignition switch output terminal: connect the red probe to the switch terminal and the black probe to ground. If the voltage is below normal or zero, it suggests damaged internal contacts or an open circuit in the switch. Also, check relevant fuses and relays for blown or faulty conditions, such as testing the continuity of the starter circuit fuse in the fuse box. Additionally, aging ignition switches are common in older vehicle models, and regular cleaning or replacement can prevent issues. If everything checks out, further inspect the battery and starter for proper condition to avoid misdiagnosis. In summary, a complete diagnostic routine helps pinpoint the root cause, enabling timely repairs to prevent breakdown risks. Remember safety first—always wear gloves when performing these checks.
Previously, my car also wouldn't start, and I initially thought the ignition switch was faulty. However, after step-by-step inspection, I discovered the real issue. My usual approach is to start with the simplest method: turn the key to the ON position and check if the lights and dashboard illuminate. If they do, it indicates that power is reaching the switch but the starting function is failing. Then, I took out a multimeter to test the switch's output wire—the voltage should jump to around 12V in the START position. If there's no change, the switch is likely faulty. Additionally, it's good practice to check whether the starter relay engages; you can lightly tap it with a screwdriver to listen for a crisp clicking sound. That time, I found the relay was stuck, and replacing it solved the problem. Experience has taught me not to overlook circuit contact issues when diagnosing ignition switch problems, especially in off-road vehicles like the Patrol, where wiring is prone to dust interference. Regularly keeping the switch dry and clean helps extend its lifespan. Patience is key when dealing with car issues—if unsure, consult a friend or technician for assistance.
