Ah, a trunk lock without a key. Fun job (done it many many times).
The hard part (in many cases) is the rear seat bottom removal. There are two clip rails on lower seat attached to floor pan. You must move the seat bottom back about 1 inch (25 cm) to unclip the seat. I find using my palm. I can hit/push the bottom of seat back enough to unpop it (it might take a couple of tries). When one side is unpopped, then go to next side. Sometimes you have snaps that hold the seat belts in place (very easy to snap back in place – providing you have three hands).
Next is to remove the seat back. Chrysler used two different methods to retain the seat backs. Either a pair of screws (3/8” – I think) or fold over tabs. After screws are removed (or tabs bent over) the rear seat back is to be raised up about an inch then it can be removed.
There will be a thick piece of sound deadening material sheet just between the seat called the trunk divider. Don’t get too rough with it for it will tear. This piece of material reduces a ton of road noise into car and is hard to believe it eliminates as much noise as it does. Raise the trunk divider up a short distance to clear the two hooks (red circles, below).
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This is a shot from a ’68 Charger – but most FMJ’s will look similar.
A SMALL person can craw though the hole – but the other 95% of us, there ain’t no way that will happen.
I have a four-foot long flat blade screwdriver just for the purpose of opening trunks like this. Once you get the trunk divider panel removed, it helps to get a flashlight (or two) or a helper to hold a flashlight. On the rear trunk panel, there will be a silver trunk latch.
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On the latch there will be an area looking like this:
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Insert a screwdriver into the slot indicated and twist (counterclockwise). The trunk will open without too much effort.
If it has been a while sense trunk has been opened, then it might be a good idea to have a helper open the trunk for sometimes the weatherstripping will hold the lid closed.
If you don’t have or want to purchase a long screwdriver – then you do have options. I have a friend who took a short piece of broom handle and regular screwdriver and used hose clamps to hold the screwdriver. Tape would work as well. I’m sure there are several other options as well (use your imagination).
One other possible obstacle might be trunk contents. Also, the spare tire might be an issue. Most cases, these can be worked around.
Now that trunk is open, the next best thing is to remove the lock cylinder and take to a locksmith to either get a key made or get it re-coded for new keys. All of Chrysler trunk locks use a rounded key – unless you have a police or taxi (which uses a matching ignition lock key).
The trunk lock cylinder is either held in with a large C-clip which can be removed with a flat screwdriver or a large nut (depending on what year car was made). Either method is not hard to do.
Trunk Lock - Original MPLS7072-2 | eBay clip-on.
Trunk Lock - Original MPLS7374-2 | eBay nut design.
The difficulty will be is if your car has a cover for the trunk lock like this:
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If so, you will need to drill out the pop-rivets out (yellow arrows, above) to get the medallion removed before the lock cylinder can be removed. It is not too hard a job to do. I can’t remember if rivets are 1/4” or 3/16”. The lock cylinder pulls right out. You “can” travel with lock cylinder removed. To open the trunk, just insert a flat screwdriver into the “missing” lock cylinder hole and turn clockwise. With that said, EVERYONE else can open your trunk, as well.
I hope this helps.
BudW