I just got the Harley adjustable back rest in the mail today for my 03 Road King and it has literally taken me 4 hours to try to figure out how to mount the lever on my bike and run the wires to the bracket and seat. I can not see anywhere on my bike where there are holes to mount the the bracket and lever. The instructions are really vague and don't give to much detail and do not make a lot of sense not to mention the picture's are so dark you can see what your supposed to be looking at on the bike. I can't find any YouTube how to videos with the adjustable back rest. I am giving up for the night and will try again tomorrow.
Has anyone used this or had any experience with this back rest?

 

I believe my 08 is probably close to what your 03 is as far as mounting. Should be a bent tab on the plate that sits in the top hole and then there’s a slot on the bottom where the bolt goes through. IIRC, you have to attach one of those wire clip speed nut doohickeys to the corresponding hole on the bike in which the bolt screws into.

 

What's up Dawg? Yes there is a bent tab on the plate and I see a couple of other slits and holes on the plate. As far as holes on the bike I don't see any unless I'm looking in the wrong area. The instructions don't really tell you. All it says is to mount the bracket and You just see a picture of the bracket on the side of the bike

 

Instructions were not worth a crap with my 2011 RKC, I just had to get jiggy with it. You can figure it out. I located my adjuster behind the left heat deflector shield. Later I even found a way to stick my Biketronics EQ for my LED lights up under it.
Yes, the instructions are useless, but get 'er done, and it will be worth it.