1. Check the Obvious:
* Obstacles: Is anything blocking the sunroof's path? Check for debris, leaves, snow, or even a child's toy. Sometimes even a slightly out-of-place seal can impede closing.
* Sunroof Tilt: Is the sunroof tilted open? If so, close it to the tilt position first, then attempt to close completely.
* Battery: A weak battery can sometimes affect power accessories. Check your battery voltage.
2. Test the Sunroof Switch:
* Multiple Presses: Try pressing the close button repeatedly and holding it for a few seconds.
* Reverse Polarity: Sometimes the switch itself can fail. Try switching the positions of the wires to rule that out. *Caution:* This requires electrical knowledge and disconnecting the wiring harness; if you're uncomfortable, skip this step and proceed to the next.
* Multiple Switches: If your Blazer has multiple sunroof switches (e.g., driver's and passenger's side), try using each one.
3. Check the Sunroof Motor and Mechanism:
* Manual Override: Some sunroofs have a manual crank for emergency operation. Check your owner's manual.
* Listen for Sounds: When you press the close button, listen carefully. Do you hear any clicking, grinding, or whirring sounds from the sunroof motor? A lack of any sound suggests a power issue or a completely failed motor. A grinding sound indicates a mechanical problem.
* Visual Inspection: If possible, carefully inspect the sunroof mechanism itself. Look for any broken parts, dislodged tracks, or binding components. You might need a flashlight and possibly need to partially remove interior trim to get a good look.
4. Wiring and Fuses:
* Fuses: Check the fuse box (usually under the hood or in the dashboard) for a blown fuse related to the sunroof. Consult your owner's manual to locate the correct fuse.
* Wiring Harness: This is more advanced. Inspect the wiring harness connected to the sunroof motor and switch for any damage, loose connections, or corrosion. This often requires expertise.
5. Seek Professional Help:
If you've checked all of the above and the sunroof still won't close, it's time to seek professional help. A mechanic specializing in automotive electrical systems or a body shop can diagnose and repair the problem. The issue could be:
* Sunroof Motor Failure: The most common culprit.
* Sunroof Mechanism Failure: Broken tracks, gears, or other components.
* Wiring Fault: A more difficult issue to track down.
* Control Module Issue: Less common but possible.
Remember safety first. If you're uncomfortable working with car electrical systems, don't attempt advanced troubleshooting. Get professional assistance.
