I did used this instructions http://www.goodeyeclosed.com./VTXRoot/AudioVox.html with few modifications. Feel free to email me with questions.
Here are few pics on how I did my Cruise control installation and few tips to keep in mind:
1- Set the sensitivity to high...switches 5 and 7 on...ONLY THIS TWO. Your cruise control will engage in less than 1 second.
2- Make a vacuum chamber at least 8" long. I did two (2) vacuum chambers, 8" and 5", but I only used the 8" and work perfect:
3- Will be a good idea to do the desmog. Like you see in my pics I have enough space to put my vacuum chamber there..I also have an Stebel horn next to the vacuum chamber (not in the pic):
4- I also cut the back of my air box to allow more air intake and enough space so it doesnt hit the vacuum chamber.
This is not my air box but I got this idea from "X'N" one of our VTXOA member. I did cut the airbox this way but I didnt installed my vacuum chamber in the air box, but that space will give you enough space between the chamber and the airbox, and the bike will get more air, it makes a different:

5- If you have a CA model, after the desmog you have a bracket where the canister was. Use clamps to install the servo in that bracket:

6- I didnt tap the bellcrank. I just put the throtle cable behind the spring and work perfect for me:

7- The gray wire from the keypad is the backlight for the keypad. Connect this wire inside the headlight to the brown and black wire in one of the two white 6 pins connectors (your bike have two).
8- I used shrink tubing for the keypad harness, with the servo harness I used the corrugated tubing and shrink tubing as you can see on the pics:
9- Seal the servo where the harness came out of the servo with clear silicone around the cover. Also seal around the keypad and behind where the harness is connected. You can seal also inside of the keypad. Drill a little hole at the bottom of the keypad to allow moisture to scape. The keypad is not waterproof.
Good luck and enjoy your ride!!!