I just discovered that the best way for me to close and keep the trunk lid of my 2015 tri glide closed is by slowly closing the lid until the gasket on the lid and the gasket on the trunk meet. Then push on the lid the rest of the way and it will then engage the locking mechanism. Mine then stays and remains closed.
Supposedly the trunks are air and watertight, so any slamming of the trunk builds up air pressure in the compartment and makes it difficult for the trunk lid to close properly.
A friend of mine stated that the above process is akin to putting the lid on a Tupperware container in which the lid is place on most of the container and then pushed down to release any excess air. It is like "burping the remaining air out of the container."
It works for me and I hope that it works for you too!!
It would be wonderful if H D would have printed that technique in the Owners Manual, OR if the people at the dealership would have been privy to that info. Instead, I was told by one person that the mechanism was out of adjustment and another one said that they can be tricky at times!!!!!

 

This is the correct way to close the trunk. Slamming it damages the seal and lock...
Raise it to the seal and push with both hands one on each corner...works for me

 

Luge the latch with a silicon based lube, helps keep the latch from popping open,

 

The only times I've had a problem with the the trunk lid was when the release button is sticking and needs lube - if I slam it, the lid'll bounce partially back open before the button pops out due to the air pressure in the compartment. As noted, lube the button...

 

Sounds like silicon lube and proper technique should do the trick for people with trunk closing issues. Makes sense to me!!

 

Also, I have now made it my habit to pull on the latch after I close the trunk to make sure that it isn't going to pop open.

 

Dealer showed us the right way to close the trunk. According to them, you close the trunk to where it is just touching the latch, then push in on the center of the door just below the latch which is on the latching mechanism attached to the trunk door. This has worked fine for us.

 

I agree about pulling on the lid, once it is closed, just to make sure that it is holding. Also, the bit of info that the dealer actually showed someone the procedure to close the trunk lid should be disseminated throughout all of the dealers. That would have saved a lot of frustration, and in particular, my dealer some time and money too!!

 

If you really want to get **** about it, you could drill a 3/4" hole in the trunk body somewhere inconspicuous, say under the seat area, and shove one of these into it from the inside:




It's a rubber duckbill check valve. It would let a puff of air out, preventing pressurizing the trunk, and then immediately seal so that nothing would get in through it.
And from here it's only like 48 cents (plus five bucks shipping, I'm sure.)

http://www.bonanza.com/listings/FLM-...FYmPHwodXgoF1A

And yeah, although I've thought about it, but I'm not going to put one in. I'll just keep doing what works as many have stated above. Well, unless I see one at a garage sale for a nickel; then, maybe.

Related question; there's a chrome piece that you can get for around the button. Not the prettiest thing, but it might help protect the area up there. BUT, has anyone seen any type of plate, placard or even a small handle that you could put on the top half of the door? That would sure make it nice for opening and closing, and not getting your grubby prints all over it. (There's a dust magnet built in that door somewhere, I swear.)

 

This is the method I use after having latch repaired and I agree is the proper way ! You also hear a click when it latches , no problems since . Ebert