Odd Problem. Door will not open

[D3vst8r96gt]

Hello Friends,

We are looking at a 1986 Merc Marquis Wagon. The rear passenger door seems to be stuck shut. I can hear the latch mechanism activating (weirdly comforting noise from my child hood) but it is stuck shut. Even leaned on it from the inside and nothing! Any ideas how to get it open? Both handles appear to work in the sense they make the door latch mechanism sound, the door lock however will not move either.

Any input is helpful.

[Broncojunkie]

My first guess would be a stuck door lock actuator, although, I've only had them stuck in the open/unlocked position. I supposed it could happen both ways.

[KevinVarnes]

I used to have problems with the exterior door handle actuator rod coming out of the handle on my '91 Crown Vic, but the interior handle would always work. Does it sound/feel like anything is happening when you move the lock button up/down? It may be a struggle, but I think you should be able to get the interior door panel off even with the door closed to be able to see what is going on in there.

[D3vst8r96gt]

I used to have problems with the exterior door handle actuator rod coming out of the handle on my '91 Crown Vic, but the interior handle would always work. Does it sound/feel like anything is happening when you move the lock button up/down? It may be a struggle, but I think you should be able to get the interior door panel off even with the door closed to be able to see what is going on in there.

Ill have to pull the seat to get the panel off. Fixing the window motors so that isn't a big deal.

The door lock is frozen and will not go up or down.

[KevinVarnes]

The door lock is frozen and will not go up or down.

Does it have power door locks? If so I would bet the door lock actuator is frozen and not letting you do anything. I've seen it on other Fords of the era. The little rubber boot that keeps moisture out of the actuator mechanism dries out and cracks and lets water and other stuff in there and then the actuator locks up. From the ones that I have seen it can keep the manual door lock knob from working when this happens.

[D3vst8r96gt]

Does it have power door locks? If so I would bet the door lock actuator is frozen and not letting you do anything. I've seen it on other Fords of the era. The little rubber boot that keeps moisture out of the actuator mechanism dries out and cracks and lets water and other stuff in there and then the actuator locks up. From the ones that I have seen it can keep the manual door lock knob from working when this happens.

Doesnt appear to be power locks actually but it is definitely frozen. Once I get the door panel of what is the best way to get the lock to disengage?

[KevinVarnes]

Doesn't appear to be power locks as in it doesn't have power locks or the power locks don't appear to be a problem? Bear in mind the power locks on these are just actuated by the front driver and passenger door lock knob buttons. There isn't a separate switch like on many cars.

My guess is once you get the door panel off you'll be able to tell what is going on. The mechanism in there isn't overly complex, but it has been a couple of years since I've been in there. There will be a rod from the manual lock knob going to the latch. You will also have rods from the interior and exterior handles to the latch. Something is either missing or rusted/frozen or both.

[wraithracing]

As stated by others it sounds like the door lock actuator had died or is stuck. The handle will move and you will hear the mechanical noise, but they will not actually open the latch due to the actuator. Odds are you will have to get inside the door to repair, but I would try one last item before attempting to remove the door panel with the door closed.

I would unscrew the door lock knob cover and using a pair of needle nose vise grip pliers try grabbing the rod close to actual panel itself. I would place a thin piece wood or something solid to protect the door panel and allow you something to gain leverage against. Clamp on the vise grips and then using a pry bar, try to pry up on the lock rod and see if you can get the actuator to move up and actually unlock the latch. If this works then it will save you a ton of time and frustration. You can also try using some spray penetrating lube and spraying or pouring it down the lock rod and allow it some time to try and loosen the actuator before attempting to unlock. Actually I might try the lubricant if you get major resistance to the prying motion. Good Luck!

[D3vst8r96gt]

Doesn't appear to be power locks as in it doesn't have power locks or the power locks don't appear to be a problem? Bear in mind the power locks on these are just actuated by the front driver and passenger door lock knob buttons. There isn't a separate switch like on many cars.
.

I am sorry I could have been more clear. I did not think it had power locks due to the there being no switch (lol the car is older than me). It does have power locks.

No noise comes from that door when cycling the power locks, not sure if thats important.

Now I have a new issue. One of the door sensors is no longer working and the map lights stay on. Checked all the sensors, there is not one that turns it off. There is one that looks like its missing the boot around it.

[D3vst8r96gt]

As stated by others it sounds like the door lock actuator had died or is stuck. The handle will move and you will hear the mechanical noise, but they will not actually open the latch due to the actuator. Odds are you will have to get inside the door to repair, but I would try one last item before attempting to remove the door panel with the door closed.

I would unscrew the door lock knob cover and using a pair of needle nose vise grip pliers try grabbing the rod close to actual panel itself. I would place a thin piece wood or something solid to protect the door panel and allow you something to gain leverage against. Clamp on the vise grips and then using a pry bar, try to pry up on the lock rod and see if you can get the actuator to move up and actually unlock the latch. If this works then it will save you a ton of time and frustration. You can also try using some spray penetrating lube and spraying or pouring it down the lock rod and allow it some time to try and loosen the actuator before attempting to unlock. Actually I might try the lubricant if you get major resistance to the prying motion. Good Luck!

Will try this when I get a chance.

[KevinK]

The mustang lock actuators spin to create the up and down movement. This is why they stick in one position. You can often pull them up and release them but never trust them as they will fail no matter how much you lube them.