1. Verify Power at the Motor:
* Use a multimeter: With the switch activated, check for power at the motor's connection points. You should have power when the switch is up, and no power when down (and vice versa for the down function). If there's no power, the problem is somewhere in the wiring between the switch and the motor.
2. Check the Wiring Harness:
* Inspect visually: Carefully examine the wiring harness leading from the switch to the motor for any breaks, chafing, or corrosion. Pay close attention to areas where the wires might bend or rub against metal parts.
* Continuity test: If you find a suspect section of wiring, use a multimeter to test its continuity. A broken wire will show infinite resistance.
* Common trouble spots: The wiring often wears near the rubber bellows that protect the wires as they move with the window.
3. Investigate the Window Regulator:
* Access the regulator: This usually involves removing the door panel (there are plenty of online tutorials specific to the 1997 Mercury Mystique that show how to do this).
* Inspect the regulator: Look for broken parts, binding mechanisms, or anything that might prevent the window from moving. Sometimes the regulator itself fails, even if the motor is good. The cable that connects the motor to the window can also break.
4. Check the Window Switch:
* Although you've replaced the control panel, it's worth double-checking the switch itself within the new panel. A faulty switch is less likely given the replacements, but it's still possible a bad connection or a problem within the new switch exists. Test for continuity as in step 2.
5. Grounding Issues:
* Poor ground connection: A poor ground connection can cause intermittent or complete failure of electrical components. Check the grounding points for corrosion and ensure a good connection.
6. Door Switch Interlock:
* Some cars have a system that prevents multiple windows from being operated at once. Check if there's a safety mechanism that might be preventing operation. It's less likely this is the problem after changing the control panel.
Important Notes:
* Safety first: Disconnect the negative battery cable before working on any electrical components.
* Consult a repair manual: A repair manual specific to your 1997 Mercury Mystique will provide detailed diagrams and instructions for troubleshooting the window system.
* Professional help: If you're uncomfortable working with car electrical systems, it's best to take your car to a qualified mechanic. They have the tools and experience to diagnose and repair the problem efficiently.
By systematically checking these areas, you should be able to pinpoint the cause of the problem with your electric windows. Remember to test for power and continuity at each stage to isolate the fault.
