I had the door lock on my Tour Master 40C fail to unlatch, even though the keylock and the remote electric lock were both actuating correctly. It was the latch mechanism itself that was the culprit, as it was finally worn enough to not travel enough to trip the pawl. I had to crawl into the driver's side window and open the door from the inside. Then I had to remove the door panel and adjust the turnbuckle that connects the exterior latch handle to the latch mechanism. Not much room to work in there and you do need to remove the lower window frame and loosen the upper one to get the door panel to move far enough back from the door itself to access the mechanisms. I bought a new latch and handle once I found the maker after a lot of on line searching -- but my readjusted turnbuckle setting was still functioning properly when I sold this coach late last year, so I gave the repalcement parts to the new owner in case the fault ever recurs. There is a thread in this forum about my door...I will try to provide a link.
Found it!! Here is the link with the part numbers of what I purchased for my coach...see the last two postings in the thread: