It's been a while but from memory it was the grey $40 plug that changed the USB back to the standard pinouts. I'm not sure about the factory USB dash connector since I didn't use or have one.
I found this from a person pitting a T1819 into a 4Runner:
T1819 radio connectors:
10pin connector:
1 -> front right +
2 -> front left +
3 -> ACC ignition +12V
4 -> battery +12V
5 -> front right -
6 -> front left -
7 -> ground
8 -> (antenna amplifier + output) now on antenna connector, you have...
Rock 40 - You are indeed jumping pin 16 to 18 with the resistor. I put my resistor as close as possible to the connector so that it didnt get damaged behind the radio. My 4runner already had the aux input jack so mine just plugged in via the adapter harnesses and the info on this forum. I'll see...
The main reason I wanted to do this is the simple fact that I despise aftermarket radios. They are all flashy and lack features unless you spend lots of money on one. I really wanted a 2 line display as well for track information. Lastly double DIN radios are really really expensive! I scored my...
Are you using the 28pin to 20 pin adapter for yours? Not sure what vehicle you're trying to put this in. If so I got mine to work with a 2.7k ohm resistor between pins 16 and 18 on the 20 pin side. I dont recall where those pins landed on the radio side on the adapter harness.
Disclaimer: I am not responsible for any damage you may do as a result of following this post. Proceed at your own risk. These are my results.
Ok here are my notes from my install of a 2012 TC t1819 into my 2008 Toyota 4Runner. I bought the PT-546-00120-AD(antenna adapter)...