I just fixed a problem with the trunk latch when the pull down motor on a 93 Cadillac Deville went out. I got the idea from another forum which I thought I would share. The trunk would latch at the first level, but then the closer would not finish pulling it down tight. I removed the motor from the unit which contains the gears, manually wound the gears down to the height where the trunk would latch down, re-installed the motor to prevent it from working loose and it works fine. This bypasses the need for having to let the pull down feature finish closing the trunk. I just didn't plug the wiring back in so no power to the closer would be working. As far as I am concerned, that feature is not important anyway. The button inside the car still releases the trunk or you can use the key to open as usual.
There were 3 bolts which releases the unit after removing about 4 screws in the plastic molded trim which hides the mechanism. You have to remove a screw to disengage the metal housing over the bendix and brushes to gain access to where you can manually screw down the latch. It takes a while as the gears move slowly when turning it by hand. I had to re-install the bendix and mounting unit to get the correct height and then replaced the housing and trim. I hope this helps.