Look for a fuse box on the passenger side, on the inner fender. It should be one of those small ones that hold two fuses.

See that you have power in and out of it. Also, is there a relay in this circuit? This would be one of those small metal boxes with wires coming from the bottom. These will go bad but they are easy to test and even easier to replace. They are very expensive new but they do show up on evil bay now and then. You can also swap one relay for another to test the windows.

You can have someone hit the switch to move the window while you have your finger on the outside of a relay. If the system uses one you will feel it click if it is working.

And don't overlook a cracked wire where the door closes. This wire bunch sees a lot of flex over the years and will crack internally. And as weird as this sounds it is possible for both sides to break at the same time. What happens is the window you use quits due to a broken wire and then you find the other window's wiring busted long ago. You just didn't know it because you never use that window.

By the way, on your motors there is no positive or negative. The switch reverses the polarity for up and down, so both wires are negative and both are positive, depending on the position of the window switch. It only takes one wire to break to shut down the whole system.