1. Identify the Problem:
* Will it open at all? This points to a problem with the power liftgate motor, wiring, switch, or possibly the liftgate latch mechanism.
* Does it open but not close? Similar to above, but the closing mechanism might be at fault.
* Does it open/close but makes strange noises? This could indicate worn or damaged components within the liftgate mechanism itself, such as the struts, hinges, or linkages.
* Does it open/close but doesn't latch properly? The latch mechanism may be worn or damaged.
* Is there damage to the liftgate itself (dents, cracks)? This requires bodywork and possibly replacement parts.
* Is the liftgate glass broken? This requires glass replacement.
2. Troubleshooting and Repair (General Steps):
* Check the fuses: A blown fuse is the easiest fix. Consult your owner's manual for the liftgate fuse location.
* Check the wiring: Inspect the wiring harness connecting the liftgate to the vehicle's body. Look for broken wires, loose connections, or corrosion. This often involves removing the interior trim panel around the liftgate.
* Test the liftgate switch: If the switch is faulty, it will need replacement. You can sometimes test this with a multimeter.
* Inspect the liftgate struts (gas springs): These lift the gate and are relatively inexpensive to replace. If they are leaking or weak, the gate will be difficult to open or close.
* Inspect the liftgate motor (if equipped): This is more involved and might require specialized tools or professional help if faulty.
* Check the liftgate latch mechanism: This could be adjusted or require replacement.
* Lubricate moving parts: A little WD-40 or silicone spray on the hinges and moving parts can sometimes solve minor problems.
* Check the liftgate limit switches: These tell the motor when to stop. A faulty switch can cause the gate not to close fully or at all.
3. Specific Repair Examples:
* Replacing Liftgate Struts: This is relatively straightforward. You'll need to disconnect the old struts and install the new ones. Plenty of videos are available online for this specific repair on a 1999 Jeep Grand Cherokee.
* Replacing the Liftgate Motor: This is more complex and often requires removing the interior trim panel and potentially disconnecting the liftgate mechanism. You'll need to know how to handle electrical connections and possibly have some mechanical experience.
* Bodywork Repairs: Dents and cracks usually need professional attention, involving body filler, sanding, and repainting.
4. Resources:
* Your Owner's Manual: This is the first place to check for troubleshooting tips and fuse locations.
* Online Forums: Jeep Grand Cherokee forums (like JeepForum.com) are great resources for finding advice and solutions from other owners who have faced similar problems.
* Repair Manuals: A Haynes or Chilton repair manual for your specific year and model will provide detailed diagrams and instructions.
* YouTube: Search for videos on "1999 Jeep Grand Cherokee liftgate repair" to find visual guides for specific issues.
Important Note: If you are not comfortable working on cars, it's best to take your Jeep to a qualified mechanic. Electrical systems and liftgate mechanisms can be complex, and attempting repairs without proper knowledge could cause further damage. Safety should always be your top priority.
