Josh's FIAT 1500 Cabrio

I know, long time no post.. Well, I have no real excuse. I haven’t been doing much on the car other than researching and buying parts. But now that the weather is nice again, I’m hoping to get some work done. Today’s topic is locks and keys.

My car only came with an ignition key. As far as I can remember, my dad never had the key to the door and trunk, and the lock for the fuel door was missing altogether.

Some time ago I spent some time researching the key blanks I’d need, and put together a page with a summary of my findings.

I decided that now was a good time to get my locks sorted out and disassembled so that I can have them rechromed. Fiat made these locks and door handles out of pot metal, which is brittle, prone to cracking, and corrodes, pitting very badly with age. So it hasn’t been easy to find ones which look like they can be repaired.

I’ve been collecting locks from various parts cars over the past few years. At this point I have three door locks, two trunk locks, three for the fuel door (one presentable) and one glovebox lock.

After soaking them in penetrating oil for a few weeks, I dropped all of these off at a local locksmith to see if they could make up keys (and get them all to use the same key).

They were able to get the door and fuel door locks on the same key, but wouldn’t open the glovebox and trunk locks because they have back covers that are crimped on and have to be cut off. That’s fair, I don’t blame them for not wanting to be blamed if the fragile old pot metal body was broken in the process.

So, I took the two trunk locks and tried to figure out how to disassemble them myself. One of them was already damaged, so I used it to figure out how to take apart the “good one”. This wasn’t easy, so i’m going to post the details here in case anyone else needs to do this on their car.

Here are the parts that make up a trunk lock assembly:

Here’s the process for taking it apart:

1. Use a zip tie around the lock body to hold the latch in. This will cause the rod to stick out the other side of the lock body, and allow a little opening around the latch.
2. Using a dremel tool with cutting wheel, remove a bit of the ridge around the cover on the back of the lock, carefully.
3. Using a small screwdriver, pry at the rear cover through the opening around the latch until it pops off. Trim more with the dremel as needed until it falls out. When I reassemble the lock, i’ll probably glue or solder the cover back on.
4. Spray the area where the rod screws into the latch piece with penetrating oil and let it soak.
5. Using a fine tipped torch (I used a butane torch), heat the latch slightly, and use vice grips on the exposed portion of the rod to get it to unscrew. Note that if you heat it too much, the spring will be ruined. Not a big deal though, it can be replaced.
6. If the rod won’t unscrew, it can be cut off. I did this with the first lock i took apart, before I was sure whether it was threaded or pressed in. If you do cut it, you’ll need to cut it flush to the lock body, then use a die grinder with a carbide burr to trim it even further, before the latch piece will come out.
7. Unscrew the screw that’s now exposed. This screw holds the sloped brass slider to the lock cylinder. Remove the brass slider.

   Trunk Lock Cylinder Components

8. Push the lock cylinder (button) out the front of the lock body. I had to use a brass drift and some gentle tapping to do this, as it was somewhat stuck.

I then disassembled the cylinder (held with one screw, the same process as with the door lock) and rearranged the tumblers until they worked with the key I had. A great explanation of how to re-key a lock can be found here.

The next challenge will be the glovebox lock. It really doesn’t look like it can be taken apart without destroying it, and I only have one. I’m actually wondering if it might be easier to find a replacement, since it seems to be a fairly generic part and I wouldn’t be surprised if it was used on other cars.

Anyone recognize this? If so, please contact me! I believe the key blank is one frequently used on british cars, so the whole lock may be the same as on some british car.

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