Why will my window motor roll down but not up?
The short explanation is that when a power window goes down but won’t go back up, the failure is usually in the up-direction circuit or the window’s mechanicals rather than the power supply. Common culprits include a faulty up-side window motor or regulator, a blown fuse or relay for the up movement, or a bad switch or wiring. Mechanical binding in the door track can also prevent the glass from rising even if the motor spins.
Understanding how a power window works
Most car windows use a single electric motor that reverses polarity to move the glass up or down, driven through a regulator and guide tracks. The up and down motions share components, but the control path for each direction can involve different fuses, relays, switch contacts, or control modules. When one direction fails while the other works, it narrows the probable causes to electrical supply, switch/wiring, or a mechanical issue in the up path.
Common causes when the window rolls down but won’t go up
The following are the issues most often reported by drivers and mechanics when the down function works but the up function does not. Each item describes what to look for and why it could fail.
- Up-direction motor or regulator failure: The motor or the window regulator can wear or seize in the up path, so the glass won’t rise even though the motor spins or can still lower it.
- Blown fuse or faulty relay for the up circuit: If the up circuit’s power supply is interrupted (fuse or relay), the motor won’t receive the correct polarity to raise the glass.
- Faulty window switch or wiring: A bad contact or damaged wire in the up control circuit (either in the door switch or the wiring harness) can prevent the up command from reaching the motor.
- Damaged door harness or grounding issues: The electrical harness through the door can wear, pinch, or corrode, breaking the up-path connection and causing intermittent or no movement upward.
- Mechanical binding or misalignment in the track: A jam, worn guides, or a mis-seated glass can cause the regulator to stall when trying to rise, even if the motor runs.
- Motor overheating or thermal cutoff: Repeated attempts to raise the window under heavy load can trigger a thermal protection in the motor, temporarily stopping upward movement.
If you’re hearing noise from the motor but the glass doesn’t move, it’s more likely a mechanical bind or regulator issue. If there’s no sound at all, the problem is more likely electrical (fuse/relay, switch, or wiring) or a completely stalled motor.
How to diagnose the issue
Below are practical steps to narrow down the cause. Perform these checks carefully, and consider professional help if you’re uncomfortable working with car electrical systems.
- Check fuses and relays for the window circuit: Locate the fuse panel and door window fuse(s); replace blown fuses and test if the up function returns. If a relay controls the up function, swap it with a similar relay to test.
- Test with the other window controls: If the car has multiple window switches (driver and passenger), compare their performance. If the driver’s up works from the passenger switch, the issue is likely with the driver’s switch or wiring; if neither works, the issue is more likely the motor/relay/fuse.
- Listen and observe the motor during an up request: If you hear the motor running but the glass stays put, the problem is likely mechanical (regulator or track). If there’s no sound, the electrical path to the motor (switch, wiring, or power supply) is suspect.
- Inspect the door wiring harness and contacts: Look for damaged, frayed, or pinched wires inside the door jamb where the harness enters the door.Corrosion at the connector or broken conductors can disrupt the up circuit.
- Check the regulator and glass alignment: With the door panel removed (safely, and only if you’re comfortable), inspect the regulator arms, cables or gears, and ensure the glass is properly seated in the bottom guide and rolling smoothly along the track.
- Test power and ground at the motor connector: If you have access to a multimeter and a safe test method, verify that power appears at the motor when pressing up and that a solid ground is present. A weak or intermittent supply points to wiring, fuse, or control module issues.
If you identify a faulty component, replacement or repair should address the symptom. In many cars, replacing a failed regulator or motor is a straightforward fix, while electrical issues may require repairing wiring or replacing the switch or control module.
Safety and when to seek professional help
Power windows involve high-current electrical loads and door panel disassembly, which can pose safety risks if you’re not experienced. If the door is difficult to access, if you’re unsure about testing the electrical connections, or if you discover damaged wiring, consider consulting a trained automotive technician to diagnose and repair the system.
Takeaways and next steps
In most cases, a window that rolls down but won’t rise points to an issue in the up-direction path—often the motor, regulator, or related electrical components, or a mechanical jam in the door. Start with a fuse/relay check, verify the switch and wiring, and inspect the door mechanism for binding before pursuing more extensive repairs.
Summary
When your window can go down but not up, focus on the up circuit: electrical supply (fuse/relay, wiring, switch) and the mechanical up path (motor/regulator, track alignment). A systematic check—fuses and relays, switch tests, wiring inspection, and regulator/track inspection—will usually identify the culprit. If you’re uncomfortable performing the checks, a professional technician can accurately diagnose and repair the issue, ensuring the window operates smoothly in both directions.
