Opening a Car Trunk

Okay, I bought a beat up used car that had no door locks keys, nor keys for the trunk. How do I get into the trunk to swap out the lock? Calling a locksmith is a possibility, I know, but I’ve got so little free time at the moment, that it’d be difficult for me to find the time to wait for him to show up and pop the trunk for me. I’d like to find out what (if anything) is in the trunk. Wouldn’t be good for me to be riding around in a car that had a body in the back or 100 lbs of coke. Plus, considering the shape the vehicle’s in, I’d like to be able to carry some tools with me, without having to worry about someone stealing them easily. (Can’t lock the doors since I don’t have a key to them, either.)

The car’s a 1990 Pontiac Grand Am (and the trunk release in the glove box doesn’t work, already tried that).

On most cars, it’s possible to get into the trunk from inside the cab. The complete rear seat must be removed.

Usually the seat bottom is retained by fixed catches at its front and by just being squished under the backrest at its rear. Removal is done by pressing the lower front edges towards the rear of the car, while prying/lifting up so that the seat will pop up when it’s clear of the catches. There’s a catch on each side (right/left), do one at a time. Then simply pull the seat bottom up and out.

The backrest will be bolted in at its bottom, usually slipping over some tabs at its top. Remove the bolts, then lift the backrest up until it’s free of the tabs, and pull it out. Sometimes it’s necessary to also remove some trim panels from around the sides of the backrest.

With the backrest out, you can crawl into the trunk with a flashlight. Find the mechanism connected to the trunk lock, and move whatever lever/rod/gizmo is necessary to release the catch, which will open the lid.

To open it again after it’s reclosed, assuming you don’t want to crawl into the trunk again, you’re going to have to remove the trunk lock cylinder and either A) take the cylinder to a locksmith and get a key made for it, or B) leave the cylinder out and figure how to open the latch throught the cylinder’s hole with a screwdriver, wire you attach to the release lever, or something like that.

All told, it may take less time to call a mobile locksmith to deal with it.

Some dealers may be able to cut keys based on the VIN (vehicle ID number).

It’s possible that the trunk release in the glove box worked by pulling on a cable. If you can find the end of this cable, clamping and pulling it with a vise grip might work.

Another technique would be to find 1990 Grand Am with a trunk that opens. Examining it will likely show you a place where you can drill a small hole and insert a tool (punch or screwdriver) that will release the latch. (But if you’re as rushed as you say, this will probably consume more time than you wish to spend.)

Should be able to get in through the rear seat - bring a light - remove lock - replace with one from a parts store - cheap and easy. The units at places like Pep Boys / Auto Zone / Advance… come with new keys so all problems solved.

Lock smith’s I know would charge at least $85 just to open the trunk and then you would still have no key.

Also, check for 12 volts at the switch in the glove box - you may just need to apply some power to the wire. Ignition key may need to be on for the button to work.

If youre going to replace the lock cyinder anyway take a big meaty flathead screwdriver, place it in the lock like the key would go in, hit it HARD and drive it in. This will either drive the lock cylinder out, break it, or give you a means of turning the lock without the key.

Replace it with an aftermarket lock cylinder or use a hook and latch with a padlock.

Since youre worried about theft, more so now that you know how easy it is to get in, I suggest getting a METAL toolbox or lockbox that you can bolt or weld into the trunk. Using odd fasteners and loc-tite secure that to the floor of the trunk. It’ll keep them in place and make them too difficult to steal for most thieves.

Because there is a good chance of doing damage to the other parts of the trunk and lock mechanism other than the cylinder

As suggested, a dealer should be able to make keys from the serial number. If not, instead of paying a locksmith to make a road service call, drive to his shop. He probably won’t charge you very much if he just has to step out his front door. (Have you every watched an expert pick an ordinary lock? It takes about 10 seconds.) He will probably be able to make you a key so you won’t have to get a new cylinder. And if the trunk lock is different from door lock, you should probably do something about that too. What happens if a “helpful” parking attendant or passenger decides to lock the door that you “forgot” to lock?

It’s a GM. They are impossible to pick.

I believe I may have seen, in a catalog, a side bar pick set for GM at my locksmith’s friends house, but I have not done that type of work for over five years and things change. If it is doable, the go to the locksmith idea is a good one.

You can get into the trunk 3 ways

  1. with a key
  2. with a trunk release in the glove box (IGN has to be on in that year model, or power run from the battery to the button)
  3. remove the back seat and crawl thru and pop the latch. WHen you view the latch from the inside, there is a slot with the lock tailpiece in it… insert screw driver and turn, this will release the lock and pop the trunk.

I do not suggest attacking the lock with a screwdriver, this can wedge the side bar on the lock and make it that much more difficult to open it.

GM did not keep key codes by the VIN number back in 1990 so your out of luck there.

If the glove box lock is still there and the locks are all original then take the car to a locksmith, he can pull the glove box lock out, make a key which gets him the first 4 cuts (out of six) then he can progress* the last two cuts on the door/trunk and Boom you have door/trunk key. It takes about 30 minutes to do this.

*Gm 6 wafer locks (which you have) follow a set of rules such as:
6 cuts or spacings
5 possible depths
the total of all 6 cuts will equal an even number
The same cut will not be used more than three times in a row
No cut will be greater or lesser than 2 of the cuts next to it.

These rulesd make it possible to progress a key from 4 cuts in about 15 attempts.

Hope that helps.

Osip the locksmith