I'm posting this so it might help a new Concours owner like myself.  I have a 2017, and I wanted to change the turn signal bulbs to LEDs, and I had a bit of struggle to find confirmation on some basic info.  So here’s what I found/did:

The LED bulbs will cause hyper-flash, and the best way to prevent that is to replace the signal relay.  It’s located on the right side of the bike, under the long, skinny body panel, just next to the seat.

I purchased this relay from Amazon, a 3-pin CF-13 type for LEDs (https://www.amazon.com/gp/product/B008C9YJ6C/).  There’s lots of options for relays, and this job requires one with 3 pins marked B, L, and E.

The new relay did not have the same connector, so I cut the wires and soldered different connectors on.  Be careful to ensure that the original wires going to B-L-E on the stock relay go to the same B-L-E on the new one.  The stock relay sits snug in a rubber holder, but the new one is a different shape.  I just used some zip ties to hold the new one in the same spot.

Much easier to get the compatible solid-state flasher "relay" that just plugs right in (if still available)...

http://www.zggtr.org/index.php?topic=17998.msg242704#msg242704

Also:

http://www.zggtr.org/index.php?topic=2236.15

Yep.  I went through this very same thing when I was recovering my Connie from the "Event".  There are electronic relays that completely eliminate the need for load resistors and, therefore, eliminate hyper-flash when switching to LED's.  That part I didn't know about but did eventually learn from this forum.  I ended up attaching the new relay to a bolt that holds something down beneath the seat.

05-30-2015  15200 mi
"Removed the factory turn signal flasher under the right rear seat cover and replaced with a solid state unit purchased from Motorcycle Superstore.  This fixes the blink rate and removes the need for load resistors."

Unfortunately the link from the other thread no longer works, and I can't find it now on THEIR site.  Here is the photo link:  http://www.zggtr.org/index.php?action=dlattach;topic=17998.0;attach=23617;image on the thread.

Dynamic Moto Power 579009  and/or 900-5515   It is almost plug and play (do need to mount it).

I did find it here:  https://www.dreyermotorsports.com/dynamic-moto-power-led-flasher-relay-detail.htm?productId=20795076 and on Amazon:  https://www.amazon.com/DMP-Motorcycle-Flasher-Yamaha-Kawasaki/dp/B00M9NGTCO

And here:  https://www.motosport.com/dmp-led-flasher-unit

Have been using it for 3 years without issue.

Nice! That would have been even easier than the one I used.

I also learned that on the 2017, the front and rear turn signal bulbs are the same: BAU15S

Nice! That would have been even easier than the one I used.

Well, at least you got it working!  Another member says this one also works just as well, plug and play: https://www.amazon.com/gp/product/B00RM26LXO iJDMTOY LF1-S-PIN

I also learned that on the 2017, the front and rear turn signal bulbs are the same: BAU15S

That is the case on all Concours 1400's of any year.  Also sometimes called "1156PY"