Voice activation switch/ steering wheel controls

I just installed a 2014 Entune Audio Plus in my 2012 access cab and everything seems to work except USB won't load pictures for start screen, just audio, not a big deal though. What I would really like to do is use the voice controls, but I don't have a "push to talk" button on my steering wheel, or any other controls. So is it possible to put those contols in? they are available fron Toyota for 300 bucks. Or just put in a push to talk button anywhere on the dash. A guy on here told me he did it with some inline resistors running from the radio ground to a push switch, but hasn't gotten back to me with the diagram. Anyone else ever done this, or the complete steering wheel upgrade?

 

http://www.tacomaworld.com/forum/audio-video/304014-2014-navigation-unit-2013-a-4.html

post 77 says that it should plug in and work ones you buy the new 14 steering controls...

read that thread...alot of info onthere
also to add pics for the start up are on here on another site and ill have to check the link when i get home

 

Thank you so much, that is a great thread.

 

I've now got everything in: 2014 entune plus non nav into 2012 access cab. Microphone mounted in overhead console, new clock spring, 2014 steering wheel controls (not pre-wired at all, had to run all 4 wires from s8 plug, plus the ground) USB/Aux plug. Everything seems to work fine EXCEPT for the illumination. I tried the ground a couple of different places including directly to the neg. terminal on the battery. So does pin 4 on the s8 have to be disconnected for the #9 ground to work and are the buttons always lighted, or just when the headlights are on. Also I noticed the radio display, AC lights, and clock all dim when I turn on the headlights, is this normal? I haven't had the truck very long and the radio has only been in a short time and I very rarely drive at night, maybe I just never noticed before.