Nice work! Glad it was quick and easy for you! Do you plan on replacing the entire latch assembly?

 

Once these motors give this non run fault, I've found that replacement is the best course of action. The motor is the same on all doors.

 

Overtheatlantic, have you found a source for just the locking actuator (motor)? When I looked for my XK it seemed they all sold the lock and latch as a set, not individually.

 

That's the easiest for sure.
They are on ebay or a wrecking yard and are easy to find

Once this one comes out, I am going to dremel open the motor case to see what exactly fails and post the results here.

 

I am testing out a small plastic piece I repurposed for the job. Not sure how long it will hold up but I still have the door panel off so easy to pull back out if needed.

I was afraid to go second hand with the unit as it may break the same as the original, especially with their age.

A tip on opening the case: there is a small hole on the lower end of the locking mechanism. I inserted the tip of snap ring pliers in there and pried it apart, working my way around. It was on too tight for a screwdriver to pry open. Also, if you are using a dremel, there are some pretty tight tolerances in there, so be careful...plus if you need to reinstall the lid, this may make it harder to secure if you dremel it (if you were to reuse the unit). Wasn't sure if you saw what went on in mine, but I'll attach a picture for you to compare to. It was the small white plastic piece that broke.

Seems like you have a good way of figuring things out though, so I'm sure you'll get to where you need to be.

 

Well one thing is for sure, if I am seeing it right once that mechanism jams for whatever reason, no amount of force is going to pull that up. Looks like a worm gear that pushes the lock assembly up and down?

 

The plastic pieces inside, though not much room, do have enough wiggle room to shift a bit if need be. I don't think it would ever be tight enough to get completely jammed, because the plastic is so small and thin. That said, I had to jam mine up with a screwdriver, I couldn't pull it up by hand while it was in the door. I think even if it ever did get jammed enough, one could break the plastic plunger arm protruding out of the mechanism in order to work the arm on the latch, or at least flex it enough to unhook from the latch arm.

Yes the worm gear works back and forth. The units were made by the company VDO, though I don't believe they make this model anymore. I contacted them via email last week and have not heard back from them.

 

Someone needs to machine that part out of brass. This reminds me of a similar failure of the headlight gears in Corvettes,Firebirds,and Fieros. They were made of nylon originally but there is someone out there reproducing the gear in brass. I guess a good machine shop can fabricate it using a good example.

 

I think so too.
This exact gear is probably in untold amount of Jags across multiple years and models.

 

my recently purchased 1996 XJR trapped me in drivers seat last nite .. no fun 65 yr old woman crawing over console to get out..I disconnected neg post, retried after reconnect - no change,..put in gear pushed the lock - no change , but I can lock all doors & unlock except driver door. when I lock from key I hear alarm and then 5 sounds at drivers door like it is trying to do something. oh I also tried the inside pull handle and found when I pull it - its harder to pull up the lock- when I let go its easier but it still doesn't unlock the door. Ideas???