1. Troubleshooting:
* Identify the Problem: Is the window completely dead, intermittently working, or making unusual noises (grinding, clicking)? This helps narrow down the likely cause.
* Check the Fuse: Consult your owner's manual to locate the fuse for the power windows. A blown fuse is the easiest fix. Replace it with a fuse of the correct amperage.
* Test the Switch: Try all the window switches (driver's side and passenger's side, if applicable). If only one window is malfunctioning and the switch is suspect, try swapping it with a working switch to isolate the problem.
* Check the Wiring: Inspect the wiring harness for any visible damage, broken wires, or loose connections, especially around the switch panel, the door jamb, and the motor. Look for corrosion or chafing. This is often a problem area in older vehicles.
* Listen for the Motor: When you operate the switch, can you hear the motor trying to run? If not, the motor may be faulty, or there's a problem with power getting to it. A faint clicking sound often indicates a problem with the motor itself or a bad regulator.
2. Common Repair Scenarios and Solutions:
* Blown Fuse: Replace the fuse (as mentioned above). If the fuse blows again immediately, you have a short circuit somewhere in the system – requires further investigation.
* Faulty Window Switch: Replace the faulty switch. These can be purchased from auto parts stores; you'll need to specify the year and model of your Blazer.
* Broken or Corroded Wiring: Repair or replace any damaged wiring. This may involve soldering, using wire connectors, or even replacing sections of the harness. Careful tracing of the wiring diagram is essential.
* Faulty Window Regulator: The regulator is the mechanism that moves the window up and down. It often fails due to wear and tear on plastic components. Repairing it can be challenging, often easier (and sometimes cheaper) to replace the entire regulator assembly. This requires removing the door panel.
* Faulty Window Motor: The motor itself can fail. Similar to the regulator, replacing the motor is often the most practical solution. Again, this necessitates door panel removal.
3. Repairing the Regulator and/or Motor (Advanced):
This requires mechanical aptitude and access to tools.
* Door Panel Removal: This is the first step in accessing the regulator and motor. Consult a repair manual (Chilton, Haynes, or a factory service manual) for your specific Blazer model. These manuals provide detailed instructions with diagrams. Improper removal can damage the door panel.
* Regulator Replacement: Carefully remove the old regulator, paying attention to how it's mounted and connected. Install the new regulator, reversing the removal steps.
* Motor Replacement: This is similar to replacing the regulator – the motor is usually attached to the regulator assembly.
* Lubrication: While you have access to the mechanism, lubricating moving parts (where appropriate) with a suitable lubricant can help prevent future issues.
4. Getting Help:
* Repair Manuals: As mentioned, a repair manual specific to your 1991 Chevy Blazer is invaluable.
* Online Forums: Search online forums dedicated to Chevy Blazers. You might find others who have dealt with similar problems and can offer specific advice.
* Auto Parts Stores: Auto parts stores can provide parts, advice, and sometimes even installation services.
* Mechanic: If you're not comfortable working on your car yourself, a qualified mechanic can diagnose and repair the problem.
Important Note: Always disconnect the negative battery terminal before working on any electrical components in your vehicle to prevent accidental shorts and injury. Safety first!
