The problem: The trunk will not open with the remote key fob, glove box button or key.
Sometimes, even if the relay is working and you can hear it click, the actuator seems to be in good condition and the trunk light works, the trunk may not open. A majority of the time the problem will be a bad ground between the trunk lid and the body. The factory design relies on the hinge to ground the trunk lid to the body. Due to corrosion or a bad connection the ground can be partially or totally lost and the trunk lid actuator will not work. The light burning in the trunk is not a good indication that you have a good ground.
Check to see if the spring that lifts the trunk lid off the latch could be the problem. Have a friend lift up on the trunk lid while you try all the methods of opening the trunk. Sometimes the spring in the latch that pushes up slightly when the latch releases can break or shift out of position and the lid will not move off the latch as it should resulting in the trunk locking again when the actuator is de-energized.
Start your troubleshooting by connecting a jumper wire between a piece of metal inside the trunk and the inside of the trunk lid that is free of paint. You may have to scrape away some paint to get down to the bare metal for a good ground. After you are certain you have a good ground between the body and the trunk lid, test to see of the trunk actuator will work. Be sure to try opening the trunk with the key, the key fob and the trunk release button. If it still will not work continue to the next step.
Once you are certain you don't have a ground problem you can start troubleshooting the components.
Listen for the trunk actuator relay to click. Try all methods for opening the trunk. You should hear the relay click. If you don't hear the relay click check for a bad fuse. If you don't have a bad fuse, replace the relay and test again. If the relay is clicking go to the next step.
Unplug the connection at the actuator. Attach one lead of a meter or test light to the connector coming from the relay and connect the other lead to ground. Try all the methods of opening the trunk while observing your meter (or test light) to see if you are getting power to the actuator.
If you are getting power to the actuator and the trunk does not open you probably have a bad actuator. To be certain the actuator is bad you can run a jumper wire with 12 volts directly to the actuator connector (not the one you just tested) and see if it will energize. If it does not energize by applying 12 volts directly replace the actuator.
Be careful not to touch the jumper with 12 volts to anything but the actuator connector terminal. Touching the jumper wire to a ground could result in the wire overheating and causing personal injury or damage to the vehicle.If the actuator works by applying 12 volts directly to the actuator you could still have a bad trunk actuator relay. Even if the relay is clicking the contacts inside the relay can be bad preventing the power from going to the actuator.