1. Identify the Problem:
* Tailgate won't latch: The problem could be with the latch mechanism itself, the striker plate (the part on the body the latch engages with), the linkage connecting the handle to the latch, or even a broken or improperly adjusted tailgate.
* Tailgate won't unlock: This could be a faulty actuator (the motor that unlocks the latch), a broken cable connecting the handle to the actuator, a problem with the lock cylinder, or a faulty wiring connection.
* Tailgate opens unexpectedly: This suggests a problem with the latch itself, the striker plate, or possibly the linkage.
* Neither locks nor unlocks: This points to a more widespread electrical or mechanical problem.
2. Troubleshooting and Repair Steps:
A. Visual Inspection:
* Inspect the latch mechanism: Look for any broken or bent parts within the latch assembly itself. Pay close attention to the latch bolt and its movement.
* Check the striker plate: Ensure it's properly aligned and undamaged. Any bending or damage could prevent the latch from engaging.
* Examine the linkage: Trace the linkage from the handle to the latch. Look for any broken or loose parts, rust, or binding.
* Check the tailgate for damage: A damaged or misaligned tailgate can prevent proper latching.
B. Electrical Issues (If applicable):
* Check fuses: Check the relevant fuses in the fuse box for the tailgate lock.
* Check wiring: Inspect the wiring harness leading to the tailgate lock actuator for any damage, corrosion, or loose connections. This often requires removing the interior trim panels on the tailgate to access the wiring.
* Test the actuator: If you have a multimeter, you can test the actuator for continuity and power. A faulty actuator will likely need replacing.
* Check the lock switch: Ensure the switch on the key cylinder or the interior switch is working correctly.
C. Mechanical Issues:
* Lubricate the latch mechanism and linkage: Apply a lubricant like WD-40 (temporarily) or a silicone-based lubricant to free up any stiff or rusty parts. This might solve a minor problem.
* Adjust the striker plate: If the striker plate is misaligned, you might be able to adjust it slightly to ensure proper engagement with the latch.
* Replace parts: If the inspection reveals broken or severely damaged parts, you'll likely need to replace them. This may include the latch assembly, striker plate, linkage components, or the actuator.
D. Getting Parts:
* Auto Parts Stores: Local auto parts stores (like AutoZone, Advance Auto Parts, NAPA) can help you identify the correct parts based on your Blazer's VIN. They usually have diagrams to help pinpoint the specific parts you need.
* Online Retailers: Online retailers like Amazon or eBay offer a wide selection of parts. Be sure to verify compatibility with your 2000 Chevy Blazer before purchasing.
Important Notes:
* Safety First: Disconnect the negative battery terminal before working on the electrical system.
* Repair Manual: A repair manual specific to your 2000 Chevy Blazer will be invaluable for detailed diagrams and instructions.
* Professional Help: If you're not comfortable working on your vehicle yourself, take it to a qualified mechanic.
This comprehensive guide should provide a starting point for diagnosing and repairing your tailgate issue. Remember to systematically check each potential problem area to pinpoint the root cause. Good luck!
