1. Identify the Problem:
* Loose Mounting Bolts/Nuts: This is the most common cause. The mirror is held on by bolts or nuts accessible from either inside the door or behind the mirror housing.
* Broken or Damaged Mounting Points: The plastic parts of the mirror housing or the door itself may be cracked or broken, preventing a secure fit.
* Loose Adjustment Mechanism: The internal mechanism that allows you to adjust the mirror might be loose, causing the mirror to wobble.
* Stripped Threads: The threads in the door or the mirror housing might be stripped, making it impossible for the bolts to grip properly.
2. Solutions:
* Tighten Bolts/Nuts (Easiest Solution):
* Inside the Door: Open the door and carefully remove the access panel (usually plastic) inside the door. This will expose the bolts holding the mirror to the door. Tighten them using the appropriate size wrench or socket. If you're unsure which bolts are for the mirror, carefully examine how everything is connected.
* Behind the Mirror Housing: Sometimes, bolts might be accessible from behind the mirror itself. You may need to gently pull the mirror slightly away from the door to access them. Be extremely careful not to break the mirror during this process.
* Repair or Replace Broken Mounting Points:
* Plastic Weld: If the plastic is cracked, you can try repairing it with plastic welder or epoxy adhesive designed for plastics. Clean the area thoroughly before applying the adhesive.
* Replace the Mirror Housing: If the damage is extensive, you'll likely need to replace the entire mirror housing. This involves removing the mirror assembly and installing a new one, which can be purchased from an auto parts store.
* Repair Loose Adjustment Mechanism:
* Tighten Adjustment Screws (If Accessible): Sometimes, there are small screws holding the internal adjustment mechanism. Accessing these usually requires removing the mirror housing (see above).
* Replace the Adjustment Mechanism (If Necessary): If the mechanism is severely damaged, you might need to replace it. This is often more complicated and may require some mechanical skill.
* Address Stripped Threads:
* Thread Repair Kit: You can purchase a thread repair kit to restore the stripped threads. This is a more advanced repair and requires some skill.
* Replace the Door Panel (Worst-Case Scenario): If the threads are severely stripped in the door itself, you might need to replace the entire door panel.
Important Notes:
* Disconnect the Battery: Before you start any work, disconnect the negative terminal of your car battery to prevent electrical shorts.
* Take Pictures: Before disassembling anything, take pictures to help you remember how things go back together.
* Consult a Repair Manual: A repair manual specific to your 1999 Oldsmobile Alero will be helpful in showing you exactly how to remove the door panel and access the mirror mounting points.
* Professional Help: If you are uncomfortable working on your car, it's best to take it to a qualified mechanic. Improper repairs can lead to further damage or injury.
Remember to be gentle and patient during this process. If you're unsure about any step, it's better to seek professional help.
