Yes ground only when closed via the loop. Just pull up and try it if is not making contact. If something got in closed like on a store bag then hope you have a key. Sometimes a wire ground to the lock is good for this too. (if people don't "shave" the lock.)
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
In Ogre's third comment above, where something gets on the loop, like a shop rag or trash bag, the latch can't make ground through the loop. Even if you don't have a key that fits the deck lock, you can insert any key partially into the cylinder, or for that matter, just use a piece of wire that has one end attached to a good ground on the body. Hold the other end to the key or face of the cylinder, have someone press the release and the latch will open.
David I wasn't complaining about mine not working while engine is running, just making sure his key was off. I think it is a good safety factor as I wouldn't want miy hatch unlatching while going down the road and not realizing the light was on until the next time I drove it. Harry
[This message has been edited by HarryT (edited 07-04-2015).]
Thanks to back when my brake system was in very poor shape, I noticed that the deck lid will not open via switch with the car running unless the BRAKE warning light is illuminated. I haven't looked at the wiring diagrams yet to verify this hunch, but they must have something to do with each other. Pull the parking brake and see if the Brake light comes on. If not there may be a problem there, but that could also just mean the parking brake sensor is messed up. You want the BRAKE warning light to come on and then try the deck lid is what I am trying to get at.
TLDR: If the car is running and the BRAKE fault light is off, the deck lid will not work. With BRAKE warning light on, the deck lid will work under power.
Edit; more clarification
[This message has been edited by Shho13 (edited 07-04-2015).]