How can I fix a 95 saturn sc trunk latch that won't lock?

SOURCE: The trunk lock on my

Yes, you can do it! ;) No "gotchas" that I can think of.

If your Saturn has a remote trunk latch release in the passenger compartment is it functioning correctly? I ask because if your car is equipped with one it is most likely cable actuated and if the cable doesn't retract after being pulled this could be an indication of the problem. There should be be a return spring inside the latch assembly that returns the latch, and cable to it's normal position, if the spring is weak or damaged it won't allow the latch to return to the correct position to catch and latch. The following procedure is for removing the lock cylinder, however it should assist you in accessing the latch assembly components for inspection. If you find a disconnected spring look for a stud, hook, etc. and reattach it. If you find a broken spring you will need to acquire a replacement most likely from a dealer parts department. If you have further questions post comments in this thread.

1. For the Sedan, disconnect the negative battery cable, then remove the trunk lid center panel assembly or reflector.
2. For the Coupe, remove the reflex panels from both sides of the trunk lid.
3. Disconnect the lock rod from the cylinder.
4. For the Sedan, remove the license plate, then remove the inner and outer retainers securing the lower outer panel. Pull the panel outward, disconnect the bulb sockets from the lamps and remove the panel from the vehicle.
5. For the Coupe, remove the screws, plastic retainers and the lower panel from the trunk lid.
6. Remove the sealing sleeve, lock cylinder retainer, reinforcement and the lock cylinder from the lower panel. To install:
   
7. Install the lock cylinder to the panel, then install the reinforcement and the retainer to the cylinder. Install the sealing sleeve.
8. Position the panel to the vehicle. For the Sedan, connect the bulb sockets.
9. Install the lower panel and tighten the retainers. For the Coupe, be sure to follow the proper sequence as illustrated, then install the plastic retainers.
10. Connect the lock rod to the cylinder using the retaining clip.
11. For the Sedan, install the center panel or reflector using the retaining nuts, then connect the negative battery cable.
12. For the Coupe, install the reflex panels. Make sure the fastener sealing feature is intact. If necessary, apply a body caulking compound to seal against water intrusion.

SOURCE: My 2003 Saturn Ion remote trunk release won't

Check to make sure the button on the trunk latch is turned from manual unlock...they made that feature so only the key will work to open the trunk that way if someone breaks in the front of your car they can't hit the trunk release and get into the trunk...may be the same thing for your remote. Hope that helps.