How to Repair a Neutral Safety Switch in Manual Transmission Vehiclesby Paul Vaughn
The neutral safety switch is located under the clutch on all vehicles that have manual transmissions. The are designed to prevent the car from being started while still in gear. Some models are adjustable and can be tightened or loosened to make them work. Others must be replaced as a unit. Their are several steps to checking out the neutral safety switch on your vehicle. The following is assuming you have a shop or garage that you can work in.
Pull your vehicle into the shop/garage. Shut of the vehicle and pull the parking brake. Make sure the vehicle is out of gear. Push the seat back as far as it will go do give yourself as much work area as possible.
Check the fuse for the safety switch. If the fuse is bad, you can replace the fuse and be finished with your work. If not, the next step is to locate the switch under the clutch. There are two screws holding the safety switch to the floor board. They are usually Phillips screws, but bring both just in case. If the mount screws are loose, tightened them. Check the engine from the drivers seat and see if that fixed the problem.
Lie back under the dash and test the continuity of the wires going to and coming from the safety switch. This will need to be done with a digital volt/ohm reader. If one wire has infinite ohms, that wire needs to be replaced. With the key on, both wires should read low ohms and 12 volts. Check the safety switch for placement and adjustment. If the lock ring is loose, this will cause erratic operating of the switch. Tighten the lock ring and check from the driver's seat if the safety switch is operating correctly.
Check the vehicles service manual for the correct distance between the clutch pedal and the sensor. Adjust as needed and you are finished.
- Take your tools under the dash with you. Getting in and out is not fun in the least.
- Having a partner is very helpful.
Things You'll Need
- Wire cutters/splicers
- Open-end box-end wrench
- Flat-tip screw drivers
- Phillips-head screw driver
- Test light
- Wire connectors (22 gauge)
- Flash light
- Safety glasses
- Make sure the vehicles wheels are chocked in the back to prevent the car from rolling by accident.
- Disconnect the battery and use a remote starter so that only you can start the vehicle.
Paul Vaughn has worked in the auto and diesel mechanics field for 10 years and as public school automotive vocational teacher for five years. He currently teaches high school auto tech, covering year model vehicles as old as 1980 to as new as 2007.