Ingress of water LHS front door of Kia Sorento, why? No seal?

Check the door ajar switch for correct operation.

https://www.google.com/search?q=2003+kia+sorento+door+switch+location

and check Fuse 16

KIA Sorento (BL; 2003-2009) fuses and relays

https://fuse-box.info > kia > kia-sorento-bl-2003-2009-...
The fuse box is located behind the cover below the driver's side of the instrument panel. The location of the fuses in the passenger compartment: KIA Sorento ( ...

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Replace the Rubber Gasket seal around the door sounds like yours has split or collapsed

Could be the heater core; on a Pinto I had years ago, that was abut the heater core location. Does the water smell of antifreeze?

the switch is bad or lose. can it be opened from both the driver side and the passenger side controller? One switch may be bad and not the other or if both switches are good than it is in the wiring to the power window or motor.

Go to online store reliable they have repair manuals I am sure you will get the solution. Here's the link
2011 Kia Sorento

You will want to taste the leak (or get someone else to do so) and make sure it is not water.
Antifreeze has a very sweet taste.
You should only need one drop, and be sure to rinse your mouth out really well afterwards.
Whenever a radiator is replaced, the hoses attached to it can also begin to leak, because the rubber hardens with age, and can be harder to seal again.
I prefer a stainless steel band clamp, not the original equipment.
A good flashlight would be a help as you look for the problem.
Be sure to check the heater hoses, and the other hoses that carry coolant, as any of them could be leaking, due to "being disturbed" or due to the possible higher pressure the new radiator is giving the cooling system.
Be blessed.

Never heard of a drain line. You have a bad seal on the head liner. Run a good bead of silicone on the perimeter of the window frame and for testing sake run one on the window itself. Wait 24 hours and spray water on it. Shouldn't leak. Take silicone off window itself and spray again. Check for leaks.

Possible that one of the door switch is faulty and so is open. You will need to check one by one , the switches, to confirm this as the open switch determines the light to be ON and makes you think that all the door swithces are faulty.

both front and rear doors have a polythene liner that must be sealed allround to stop water ingress, chances are its the front one at the rear.you need to take off the door panel and use duct tape to seal it.
panel is just clips/self tappers.(you could use a flourencent dye but that is expensive but quicker)
you must find the leak asap cos the ecm is under the front seat.

yes but if leak is from hose on back of motor they are sealed by an o-ring so thats all you need