You should pull the door card and check to ensure the motor is getting full current and that the wiring is in good shape. Additionally if they have been this way for a while, they might be stuck. You could try using a credit card and run it around the inner and outer rubber seal around the glass to break any bond, possibly also using a window glass suction cup to apply some downward pressure on the glass as you work the switch. My passenger rear window sometimes sticks because it is the least used, but freeing it up, has been working ever since. Now I periodically run all the windows just to keep them free. Also graphite powder is great for lubing the window channels.

Good luck

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)