Here's a breakdown of how to troubleshoot and potentially fix the problem:
1. Identify the Broken Parts:
* Examine the white parts: Carefully inspect the small white pieces. They might be plastic clips, pieces of the regulator's plastic casing, or even part of the cable mechanism itself. Pictures would be extremely helpful in diagnosing the issue.
* Inspect the Regulator: With the door panel off, carefully examine the window regulator. Look for broken plastic parts, frayed or broken cables, or any signs of binding or damage. The regulator is usually a complex assembly of gears, cables, and motors.
2. Troubleshooting and Repair Options:
* Minor Damage (missing clips): If only small plastic clips are missing, you might be able to find replacements. Search online retailers (e.g., Amazon, eBay) for "Buick Rendezvous power window regulator clips" or specify the year and model for better results. You may even be able to use small zip ties or similar fasteners as a temporary or even permanent fix.
* Cable or Gear Damage: If the cables are broken or the gears are stripped, repairing it yourself might be difficult and possibly not cost-effective. The regulator is often a single unit, and repairing individual components can be challenging.
* Replace the Regulator: This is the most likely solution if the damage is more significant. You can purchase a replacement window regulator from auto parts stores (like AutoZone, Advance Auto Parts, or NAPA) or online retailers. Make sure you get the correct part number for your specific year and door (driver's side or passenger's side).
3. Replacing the Window Regulator (If Necessary):
This is a moderately involved repair job, but it's manageable with some mechanical aptitude and the right tools. You'll need:
* New window regulator: The correct one for your vehicle.
* Screwdrivers (Phillips and flathead): A variety of sizes.
* Possibly a socket set: Depending on the mounting bolts.
* Pliers: To help with cable connections (if needed).
* Possibly a panel removal tool: To avoid scratching the door panel.
* A Shop Manual (optional but helpful): A shop manual specific to your 2003 Buick Rendezvous will have detailed instructions and diagrams. You can often find these online (often as PDFs) or at auto parts stores.
Steps for Replacement (General):
1. Disconnect the battery: This is crucial for safety.
2. Remove the door panel: This usually involves removing screws and carefully detaching clips. Consult a repair manual or online video tutorials specific to your year and model for detailed instructions.
3. Disconnect the window motor and any electrical connectors.
4. Remove the old regulator: This often requires removing bolts and carefully detaching the window from the regulator.
5. Install the new regulator: Reverse the removal process, ensuring the window is properly seated and all connections are secure.
6. Reconnect the electrical connectors and motor.
7. Reinstall the door panel.
8. Reconnect the battery.
9. Test the window: Make sure it goes up and down smoothly.
Important Note: If you're not comfortable performing this repair yourself, take it to a qualified mechanic. Incorrectly installing the regulator could damage the window or the door mechanism. Also, if the motor is faulty (unlikely, but possible), that would need to be replaced as well. The motor is usually part of the regulator assembly in these cars.
