2004 GMC Yukon Door Locks

With the battery on the truck dead the keyless entry will not work because there is no power to work the power locks. Often on vehicles with keyless entry the key locks on the doors never get used and tend to freeze up. You can likely loosten the door key tumblers back up witha good penetrating oil. Spray some oil into where you would insert the key using the tiny tube that comes with the penetrating oil. Try to work and wiggle the key after adding the oil. If it still doesn't open then squirt a little more and give it some time to work. Eventually it should loosten up enough to be able to turn the key and unlock the door (the old fashoned way :) ).