Thought I'd report back to you all!
I've been wanting to upgrade the factory speakers for a while. I wanted marine grade speakers; those summer deluge's always seem to find me on long trips. With Randy Brewster's adapters, I was able to go with 6.5" Polk speakers; and a 300 watt Rockford Fosgate amp.
First I decided to strip the bike down before proceeding. I decided it would be easier to work on if I just had everything out of the way. Frankly, I think people spend more time and energy trying NOT to just take parts off, than they would if they took parts off. It takes less than 5 minutes to remove the fuel tank on the Vaquero; and I'm sure I would spend more time than that fishing wires under it. So off the tank went:
Of course, the fairing also had to be removed. That's not difficult, but it is a little tedious and time consuming. In the process, I also decided to re-wire my trailer lighting setup while I was at it. So I removed the saddlebags and trim. Because I wanted to run the amp directly to the battery; I wanted to move my trailer lights OFF of the battery. I use an isolator circuit, so I just need a source of 12V power. So I just ran those wires to the accessory leads under the seat. Works just fine.
Amp mounted. I realized what a dolt I was running the power alongside the speaker cables. So I did reroute that afterwards. But that's it! Bolted onto a little bracket, fresh wires running to both speakers.
The factory speakers connect to the stereo via a releasable 'clip'. I wanted to limit the amount of factory wiring I cut. So I took the wire that normally runs down from the speakers to the connector on the bottom side of the fairing. I cut the speaker connections off of that, and soldered it to the amplifiers proprietary high-level input harness. So it all plugs right in and can easily be returned to stock; either by soldering on new speaker connections into that factory lead, or just replacing the factory lead. MUCH easier than if I had cut into the bikes main wiring harness.
Here's a shot of the 6.5" speakers mounted. I struggled to find some speakers whose grille was attractive. My GOAL was that if someone walked up to my bike and didn't know better; they'd think it was stock. Obviously, a Vaquero owner is gonna know those are aftermarket; but I didn't want a crazy "aftermarket" look to it. I think those look pretty good.
And the last step before I buttoned it all up; I mounted a Garmin Zumo 595LM ahead of a trip through the Blue Ridge Parkway in a couple of weeks. The fairing 12v accessory leads give absolutely no slack; but they are a super handy place to run wires for the Zumo. Once the fairing is already off, anyway. Had I not already had the fairing off; I probably would've spliced it in to the wires running to the under-seat 12v accessory leads; that are currently occupied by my trailer light isolator kit. (If you look at the wiring diagram; both accessory leads go to the same fuse; so they're on the same circuit regardless). The trailer lights are LED, and the Zumo draws just 1 amp, so it's no big deal.
Under the fairing, there is a GPS audio connector. You can spend $30 to buy the adapter from Kawasaki; but it's something you could easily make yourself with a soldering gun and a trip to anywhere that sells electronic connectors. I elected not to connect it; choosing instead to use my bluetooth headset exclusively. If I change my mind; I can go into the fairing again. Although it's currently all taped up; there is an audio lead in the fairing for the Zumo, that would just have to be connected to the factory stereo.
All in all; I'm fairly happy with it. It's much louder. Audio quality isn't fantastic; I suspect a lot of that is the factory stereo. The install wasn't too difficult. Unfortunately, it was ME doing the install; so the fairing came off a few times. After buttoning it all up and taking it for a test ride, it became apparent that my headlight wasn't working. So the fairing came off again so the idiot who took it off the first time (me) could plug the headlight back in. Somewhere in THAT process, a windshield nut had come loose; so it had to come off a THIRD time. But other than that, a project well done.
Blue Ridge Parkway; here I come!