How to Test a Neutral Safety Switch in 3 Steps

In every automated car, there is a neutral safety switch. This electronic component prevents the engine from starting accidentally. So, users can start their vehicle only when the gear is in the “Park” mode. Sometimes, this switch may start malfunctioning or stop functioning at all. In both cases, it’s necessary to know how to test a neutral safety switch to find out whether the switch is working or not.

How to Test a Neutral Safety Switch

If you find any anomaly in the functions of this switch, find out the actual source of this problem. Go through these simple steps to test the neutral safety switch.

1. Locating the Switch

Lots of people don’t know the location of this switch even after driving for many years. If you are unaware of its position, carefully read the service manual to have information about its location and functions.

The switch is likely to be on the inside of the transmission cage, and it looks like a cigarette lighter. It can also be in the gear shifter or on the side of the transmission.

neutral safety switch
Fixing neutral safety switch. (Source: CarBibles)

2. Inspecting the Wiring

After finding the switch, you need to check its wiring. It has wires that establish its connection to the starter coil. This switch will be on “Open” when the transmission is in gear. As soon as you take the ignition switch to the “Start” position, the starter will begin to get the current.

During these processes, you need to ensure that the transmission is in either “Park” or “Neutral” mode. You can get a complete idea about the wiring layout of your vehicle by consulting the service manual. Finally, detach the connection between the switch and the wiring connector.

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3. Testing Power in the Switch

To test this switch, put the gear in the reverse position and then place the key in the ignition switch. Don’t kick off the car’s engine during this time. Use a 12-volt test light to check the presence of power in the wiring harness. If there is power, the test light will light up.

Through this test, you can also tell if the circuit is working correctly or not. Now, attach the wiring connector to the neutral safety switch. If there is no light, look out for damaged or loose connections by testing all the wires. If the wires are functional and still the light is not getting any power, replace the neutral switch.

You can also move the car’s shift levers to different positions while starting the engine to check the requirement for switch adjustment. Here, you will be bypassing a neutral safety switch. Follow this procedure to perform the bypass securely:

  • Try to start the car while the gear is in the “Park” mode.
  • If the engine is not cranking, press the brake and try to start in the “Neutral” mode.
  • If the engine starts after the second step, the switch has become faulty.

Conclusion

Now you know how to test a neutral safety switch. Follow these steps to find out if you have to adjust the switch or if the problem stems out from some other sources.