steering control wire question

You don't mention what is your unit and the picture is a bit blurry; what is the labeling on the pink one?

Anyway, I would guess the pink one is the BRAKE wire.
Connecting this one to a ground will let you watch video while driving.
(Not recommended; it's even illegal in some states...)
The red and black wires are probably extra wires in case you want to power up other hardware like a CD changer or something.
So as it is, you probably don't need to connect these wires to find out if the unit is working.
Better check your docs though! Sometimes they post the meaning of each wire onto the unit itself...

 

Oh OK different story then.
In this case, this wire probably connects into the 20-pin harness.
You don't say if you have a special adapter for the steering wheel or if it is builtin in the unit.
So I guess the best thing is to check out that first.
You may also look at the sticky post at the beginning of this forum.
They have an explanation oh what needs to be done when wiring those adapters.
Here: http://priuschat.com/forums/gen-iii...-toyota-prius-model-ii-head-unit-upgrade.html

 

you know, I'm confused a bit at your picture...
The RED and BLACK seem to be together going into a tiny plug.
The PINK wire is lose.
Now, the steering wheel wires on the Toyota wiring diagram are:
PINK: ground
RED: SW1 pin 7 on the 20 pin connector
GREEN: SW2 pin 8 on the 20 pin connector

Could it be that your BLACK is actually the GREEN or SW2?
Then RED would be SW1 and PINK the ground?
In other words, are you absolutely sure that the labeling is as you said in your initial post?

 

OK.
SW2 is used for Mode and Voice.
SW1 is used for VOL+,VOL-, SEEK+,SEEK-
Assuming your unit doesn't need an adapter AND that the voltages are compatible, it should work.
So my guess is your RED is SW1 and PINK is SW2.
Just because your RED matches the car RED and also the labeling says line 1.
If not, then obviously it's the other way around.
You can try one wire at a time to make sure.

But before doing anything else, I would advise you to check with the company to confirm.
Just saying because I know some cars are using different voltages for steering wheel control.
If this unit has not been made specifically for Toyota's, you better check...

 

Great! Glad I could help.
Show us some picture some time of your new unit and what it could do, etc.

 

Wow! That's impressive. Very nice piece of work and installation.

(BTW about the gap with the trim, we had to put washers too for the Ottonavi unit and it ended up just perfect.)