My power window won't go up

If your front driver's window only goes down and not up, but the other windows work fine, the issue is likely with the motor or the window regulator mechanism.

You've already confirmed that power is reaching the motor when you press the switch in either direction, so it's possible that the issue lies with the motor itself. It could be that the motor has worn out or is stuck in a position that only allows it to roll the window down. You could try tapping on the motor with a rubber mallet or similar tool to see if it will start working again. If that doesn't work, you may need to replace the motor.

Another possibility is that the window regulator mechanism is damaged or broken. The regulator is the mechanism that moves the window up and down and it could be that it is jammed or has broken parts. In this case, the regulator would need to be replaced.

It's best to have a professional mechanic diagnose the issue and make the necessary repairs, especially if you're not familiar with working on car windows.

If the motor is receiving power in both directions but only turns in one direction, and you've ruled out issues with the window regulator and motor connections, the switch could indeed be the problem. Here are a few things you can try to test the switch:

1. Check the switch contacts: You could try removing the switch from the door panel and inspecting the contacts for any signs of damage or wear. If the contacts are dirty, you could try cleaning them with a small brush or compressed air.
2. Test the switch with a multimeter: You could use a multimeter to check the continuity of the switch contacts. With the switch in the "up" position, test for continuity between the two contacts that should be connected when the switch is activated. Repeat the test with the switch in the "down" position. If there's no continuity in one direction, the switch may be faulty.
3. Swap the switch with a known-good switch: If you have access to a known-good switch from another vehicle, you could try swapping it with the suspect switch to see if the problem persists. If the window now works in both directions, the original switch was likely the problem.

If you determine that the switch is faulty, you'll need to replace it. You can usually find replacement switches at an auto parts store or online. Be sure to get a switch that's compatible with your vehicle's make, model, and year.