Here are a few things to check:
1. Check the fuse. The fuse for the rear left power window is located in the fuse box in the engine compartment. It is a 15-amp fuse. If the fuse is blown, replace it with a new one of the same amperage.
2. Check the wiring. There may be a loose or broken wire in the circuit that powers the rear left power window. Check the wiring under the driver's seat and in the rear door jamb. If you find any loose or broken wires, repair them.
3. Check the window regulator. The window regulator is the mechanism that raises and lowers the power window. If the window regulator is damaged, it will not be able to power the window. You can check the window regulator by removing the door panel and inspecting it.
4. Check the window switch. The window switch is the button that you press to raise or lower the power window. If the window switch is damaged, it will not be able to send a signal to the window regulator. You can check the window switch by testing it with a voltmeter.
If you are not comfortable checking these things yourself, you should take your car to a qualified mechanic.
