1. Regulator Problems: This is the most common cause. The regulator is the mechanism that uses the motor's power to physically raise and lower the window. Problems include:
* Broken cables: The cables that connect the motor to the window may be snapped, frayed, or off their tracks. This is a very common failure point.
* Bent or broken regulator parts: The plastic or metal parts of the regulator can crack, break, or become misaligned, preventing the window from moving even though the motor turns.
* Seized regulator: Over time, dirt, grime, and corrosion can cause the regulator to seize up.
2. Motor Issues (Less Likely): While less common than regulator problems when the motor is running, it's still possible:
* Weak motor: The motor might be struggling to overcome resistance from a faulty regulator or binding window. This is more likely to manifest as slow or jerky movement, or a loud straining sound.
* Internal motor failure: While less likely if you hear the motor running, there's a chance of a partial failure inside the motor itself that prevents it from effectively transferring power.
3. Switch Problems (Less Likely): A faulty switch can sometimes send confusing signals, causing the motor to run without properly engaging the regulator. However, this is less likely if the motor runs continuously instead of intermittently.
Troubleshooting and Repair:
1. Inspect the Window Mechanism: Start by carefully removing the interior door panel. This process varies depending on the specific door, but typically involves removing screws and carefully prying the panel away from the door. Consult a repair manual or online resources for your specific year and model. Once the panel is off, you'll have visual access to the regulator and window mechanism. Look for:
* Broken or frayed cables: These are usually easy to spot.
* Bent or broken regulator parts: Examine all the moving parts carefully.
* Obstructions: Check for anything that might be jamming the window (e.g., debris).
2. Test the Motor (with caution): With the panel removed, carefully try to manually move the window up and down. If it moves freely, the problem is likely the regulator. If it's still stuck, the motor might be weak or the regulator severely seized. Caution: Be very careful not to get your fingers pinched in the mechanism.
3. Lubrication (if appropriate): If you suspect a seized regulator, *carefully* apply a penetrating lubricant (like WD-40 or a silicone-based spray) to the moving parts of the regulator. Let it sit for a while to penetrate before attempting to move the window again. *Do not over-lubricate.* Excess lubricant can attract dirt.
Repair Options:
* Replace the Regulator: This is often the most effective solution. You can find replacement regulators at auto parts stores or online. Replacing it requires some mechanical skill and familiarity with tools.
* Repair the Regulator (if possible): In some cases, you might be able to repair a broken cable or replace a damaged part of the regulator, but this is usually more challenging and may not be cost-effective.
* Replace the Motor: This is less common in this scenario, but it's an option if the motor itself is faulty.
Important Notes:
* Consult a Repair Manual: A repair manual specific to your 1988 Chrysler Fifth Avenue will provide detailed instructions and diagrams for removing the door panel and accessing the window mechanism.
* Safety First: Always disconnect the battery's negative terminal before working on the electrical components of your car.
* Professional Help: If you're not comfortable working on car repairs yourself, take it to a qualified mechanic.
The most likely culprit is a faulty regulator. Begin by carefully inspecting it after removing the door panel, and that should give you a clearer picture of what needs repair or replacement.
