2003 Safari Rear Door Question

My inlaws have a Safari Van with dutch style doors at the back. The keyless entry works, the problem is the button on the outside of the door when pressed will not release the glass(upper part). They also said at one time they were able to insert the key in the button, turn it to the left, and all doors would unlock. This is also not working. Both driver and passenger lock buttons on the door panel are not working either. Anyone have any ideas what would be the culpret? Thanks in advance!

Hi all. If anyone does run into this problem, there is a separate fuse located by the cigarette lighter. That is the problem. Replaced fuse, and all is working well now.