[RIP]

Not sure how they are labeled but there are two PTC circuit breakers (no fuses) for the windows on the junction block under the dash. Don't bother with them though. If they were popped you'd have more than rear window problems and they would still work intermittently.

Either check continuity through the switch contacts to verify the switches or gain access to the motor connections and check for power. If you consistently get and loose power with switch movement then the motors are shot. The motors fail more often than switches. A continuity check on motor windings tells you half the story. Most often it's motor brushes that wear and decrease current draw and power under load.