What year is your kia?
Do you know if you have power and ground to the window motors?
DO you know if you have power at the main power window switch?
You might have to pull it out (leaving it plugged in) and check for power with the key on
Well to diagnose it, you will need a test light or a voltmeter. You need to see if you have power at the main switch with the key on. If you have the correct power at the right terminals at the main power window switch, then you need to test each circuit individually. You will need to see if you are getting a power and ground being sent from the master switch to each of the front of the power window motors. You should be able to test this right at the switch.
If you need a wiring diagram, let me know!
YES... you are looking for 12 volts (or close to 12 volts).
If there is 12 volts and a good ground coming from the switch then you will need to check it at the motors themselves. If there still geting the power and ground when you try to roll them down via switch, the power window motors are bad.
Here is a wiring diagram.
The yellow wire and the blue wire with yellow stripe should have power to it with the key on.
Here are the instructions to remove the door panel. This is for a 2005, but it should be very similar. Yes, after the screws are out, the door panel just pops off.
Does this help? Did you have any further questions?
I hope this helps! You can always accept my answer now, and repost back again later on if you have any more questions. If you want to discuss it some more just hit "reply", it's free to do so otherwise don't forget to hit "accept" and leave positive feedback if you found my answer helpful.