BIG CHEVY 3600, on my 53 you cannot push the handle forward when the door is open. I am assuming all AD's are the same.
GM has made it impossible to lock your keys in the truck. The driver's door is locked by pushing the interior handle forward and then the passneger's door needs to be locked with the key. If you have door locks on both exterior handles, one must be locked with the key.
AD, your right, I checked and could not lock the door without the key. What's weird is somehow my AD back in the early 60's was able to lock itself because I used a local locksmith to unlock it on at least 1 occasion. (slow learner) I don't know what I did but whatever it was didn't workout well for me. A good friend of mine's dad had a glass shop and replaced vent glass twice.
