1. Preparation:
* Gather Tools: You'll need a socket wrench set (likely including a 13mm or 10mm, depending on your specific vehicle), a flat-head screwdriver, possibly a pry bar, and a new neutral safety switch (ensure you get the correct one for your Jeep's transmission – automatic or manual). A ratchet and extension might also be helpful.
* Vehicle Access: Park on a level surface, engage the parking brake firmly, and chock the wheels. You'll need access to the transmission area, often underneath the vehicle.
* Consult a Repair Manual: A Haynes or Chilton manual (or a trustworthy online repair guide) will provide specific torque specifications and detailed pictures for your year and model. This is highly recommended.
2. Accessing the Neutral Safety Switch:
* Location: The NSS is usually located on the top or side of the transmission. Its precise location varies slightly between engine types (e.g., 4.0L inline-6 vs. 4.7L V8). Your repair manual will show you exactly where it's located. You may need to remove some underbody components for better access.
* Removal of Components: Depending on your vehicle's configuration, you might need to remove the air intake system, parts of the exhaust system, or other components to access the switch clearly.
3. Replacing the Neutral Safety Switch:
* Disconnect Electrical Connector: Carefully unplug the electrical connector from the NSS. Take a picture or note how it is connected to aid reassembly.
* Remove the Switch: Use the appropriate socket wrench to remove the bolts holding the NSS to the transmission. Sometimes, it might be held in place by a clip or retainer, requiring a pry bar (use caution to avoid damaging the transmission).
* Install the New Switch: Carefully install the new neutral safety switch, ensuring it's seated correctly. Tighten the bolts to the manufacturer's specified torque (found in your repair manual).
* Reconnect Electrical Connector: Plug the electrical connector back onto the new NSS, ensuring a secure connection.
* Reassemble Components: Reinstall any parts you removed to access the switch.
4. Testing:
* Reconnect Battery: Reconnect the negative battery terminal.
* Test the Functionality: Start the vehicle and check that it starts only when the transmission is in Park or Neutral. Also test that your reverse lights function properly. If there are any problems, double-check all connections.
Important Considerations:
* Transmission Fluid: Be cautious not to spill any transmission fluid during the repair. If you do, you might need to top it off afterwards.
* Torque Specifications: Always refer to your repair manual for the proper torque specifications when tightening bolts. Over-tightening can damage the switch or transmission.
* Difficulty: This is not a beginner-level repair. If you're not comfortable working under your vehicle or are unsure about any step, it's best to take it to a qualified mechanic.
This is a general guideline. Always consult a repair manual specific to your 1999 Jeep Grand Cherokee Laredo 4x4 before attempting this repair. Improper installation could lead to vehicle failure or damage. Safety is paramount – if you're unsure, seek professional help.
