The trunk lock cylinder is pretty close to the door lock cylinders and is fairly easy to recode – other than they are designed to take different keys (except for police or taxi versions, which uses the ignition key).
The problem with recoding door and trunk lock cylinders is finding parts.
Most older locksmiths will have the parts. Most newer locksmiths – will not.
I have a huge Chrysler only pin kit in my garage (a 10,000-piece set, I think) which is made by (of all people) Briggs & Stratton. The only thing I’m missing is the gauge set for it
The tiny pins are made of brass. There are bottom and top pins of varying lengths. Combined, they come to a certain length (I think, 3/8” combined). The bottom pin, the part that contacts key interacts with the “V” grove on key. Combined, the “V” grove and the bottom pin also come to a combined measurement (but not sure of that measurement).
If you lay out the bottom pins on a table, and they are touching the key in respective key groves, you should be able to lay a straight edge on top of pins and they all touch the straight edge (no gaps)
This picture is of a house lock – but the pin operation is the same. The pin diameter and length are different, though.
In this case, there is one pin slightly off. Just enough that lock will not operate.
This is a picture of a door lock cylinder. Trunk lock cylinders look close, but not quite – mainly at the end. This is first one I’ve ever seen that is gold in color, and not gray metal.
This is a trunk lock cylinder. Pink arrow is detachable via the spring at white arrow. Each body style uses a different rod, so most of Chrysler trunk lock cylinders come with several rods to chose from (or you can reuse your existing one).
This one is clip on. About 1/2 of FMJ's use clips (black/blue arrows) and other half of trunk lock cylinders have a large metal nut. As long as you have the nut (or clip), it doesn't matter which one you use.
The top cap pops right off (brown arrow, second picture up) – but be VERY careful, because there is several springs and small pins just WAITING to ESCAPE (and never to be seen again). The springs can be attracted to a magnet, as well as the cap. The pins are brass, and the only thing that attracts them, is a vacuum cleaner (again, never to be seen again).
If you attempt to take one apart – so somewhere where you can control the small parts – if they wish to escape (and not roll off, get blown away with a fan or played with by a pet cat, get jumped on by a cat, and so on). By the way, I don’t have cats any longer, for some odd reason . . .
If your eyes don’t work as well as they used to, using reading glasses (or something) may be a valuable tool.
Also, ff you attempt to recode one of these yourself, see if you can get ahold of a small and shallow multi-pocketed tray, like for beads, jewelry, etc. and keep both pins together (for each hole). The springs are the only thing that doesn’t matter as to which hole. When Removing the pins, keep a finger over the other holes and turn cylinder upside-down – to keep things from getting mixed up. Sometimes it gets mixed up without trying.
My experience is a new lock cylinder will have 2 to 4 pin combo’s you need - but the other 1 to 3 pin combos are duplicates or not needed ones. In most cases, if keying to a new key (like to match a new ignition key), a new lock cylinder and using your old lock cylinder will give most people enough parts to make full set.
If you don’t quite have enough pin pairs, you can elect to install lock cylinders with less than a full set of pins. Thirty or forty years ago, it wasn’t recommended. Now, people hardly have these keys on them, so chances of someone getting a random key to fit your is already very slim and then the chance of the random key working on your (less a pin) cylinder is still more slim chance (or, however you want to say that).
Besides, if a thief is determined to steal your car – a lock cylinder (except for maybe a broken one) will slow him down but won’t stop him.
Generally, it is not a bad idea to just take your new key in with lock cylinders and get a locksmith to do it. The job is not difficult, but the chances of losing parts or getting pins mis-matched is high (I’m an expert on that part). Also working on small parts is not as easy for me as it once was. Using metal needle nose pliers is not recommended, for it is easy to scratch the brass. Insert a scratched pin into a lock cylinder – it might never come back out.
This is an example of the newer Chrysler double-sided lock cylinders. They use wafers instead of pins. Also, they are numbered (you can see numbers stamped on the brass).
This picture is for a BMW – but it looks just like a Chrysler setup, somewhat. These are easier to work with – but those lock cylinders are designed to only assembled one-time. I’ve tried to recode them, and they can give a person never-ending grief if recoded a second time.
BudW