Mechanics

Ignition Switch Wont Turn

An ignition switch is designed to utilize a key that controls the main electrical switch in your car. This switch controls the engine starter, main control systems and other various systems.  The key is used to keep unwanted users from operating the vehicle. This key and lock are much like any other lock and key assembly. All lock assemblies have a periodical maintenance schedule. This lock service includes cleansing of the key and internal lock assembly. 

After the cleaning maintenance has been performed a small amount of lock lubricant should be added to the internal lock tumbler. The car ignition lock is subject to pressures and vibration through normal usage. When this condition occurs the key switch will not operate, this could mean the switch will need to be replaced. There are various other conditions can cause the ignition switch not to turn, we have listed the most common ones below.

Ignition Key Lock Tumbler
Ignition Key Lock Tumbler

Troubleshooting an Ignition Switch That Wont Turn

Step 1 - Most cars have power steering, the power steering uses hydraulic pressure to assist the driver in steering the car. When the engine is shut off the hydraulic pressure is relieved. If the steering wheel is turned when the car is shut off the "lock pin" that holds the steering wheel in one place is now under pressure. Place your hand on the steering wheel and pull it in one direction and then the other while turning the ignition switch. This should release the lock pin and allow the switch to operate properly. (Note: always shut the car engine off when the steering wheel is in the straight position)

Step 2 - Dirt and debris inside the key lock can cause the tumbler assembly to malfunction by not allowing one or more of the key followers to operate. Protect your eyes and use pressurized air to clean the internal lock mechanism. Next, clean the key with a mild detergent and dry. Then use a lock lubricant and move the key in and out of the lock tumbler while trying to turn it.

Step 3 - The ignition key is designed to hold the key followers in the correct place to allow the cylinder to turn. If the teeth of the key wear down it will not operate the lock properly. Try a spare key in the lock, if a spare key works the lock, have copies made of that key and discard the key that doesn't work anymore.

Step 4 - A car with an automatic transmission utilizes an interlock cable that holds the car in park when the key is in the off position. If the gear shift selector is not completely in park it can cause the ignition switch to malfunction. Check the gear selector to make sure it is completely in the park position.

Step 5 - The ignition switch has many components; on some vehicles the actual ignition switch is down on the steering column and connects the key and tumbler by a mechanism. If this mechanism or the switch fails it could cause the key switch not to turn. To repair this problem disassemble the steering column and repair or replace the broken parts as needed then reassemble and recheck.

If further assistance is needed, our certified car repair technicians are ready to answer your car questions.

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AUTHOR


Written by
Co-Founder and CEO of 2CarPros.com
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2013-08-16)