Wiring a VS stereo. HELP!

[salnys]

Hey guys
Problem.
I have recently been given a second hand pioneer head unit out of a mates old car. Yes, before you ask, it was working fine when it was in his.
NOW
Upon consulting this site i have gone about trying to install it.
I have had the wires running into my passenger seat for days now and this is what i have concluded:

The black wire on the back of the head unit is and should run to the ground
The yellow wire (labelled battery) should be connected to the battery wire.
The Red wire (labelled ACC) should be wired to the constant.

These are the only wires i need to link if i want the damn thing to turn on, correct? The rest are 4 pairs all with matching colours so i guessed they are the speaker wires.

Upon consulting this site's wiring chart, i've concluded that
The black wire should be linked to the Black/white wire.
The yellow wire should be linked to the orange/violet wire
The red wire be linked to the red/yellow wire.

Nothing happens. HELP!!!!!
EDIT: everything i written here is just what i've done. I don't knwo if any of this is correct, but it is what i have arrived at.
The wiring chart i used is here:
http://www.justcommodores.com.au/temp/wiring.htm
credit to Darren

[sweefu]

have you tried using a different ground spot incase the one you are currently trying was damaged when you took the old H/U out? This has been the problem for me before.
|Goodluck mate.

[HCVP]

If its not turning on, its most likely an earth wire issue. Have a good look at it, and make sure there's a proper connection. Make sure you havent blown any fuses during the install. Check both your under dash fuses, and the fuse located on the back of the head unit..

Also have a look at the wires going onto your ISO (this is the plug, coming from the head unit) if it's been installed and removed a few times, sometimes it's possible for one of the wires to dislodge from the ISO...
Coming from the cars wiring harness, the plain yellow wire, (also a little thicker than the others) is your accsesories wire.
The orange wire, is the constant 12V wire.
I'm not %100 on the Pioneers wires though..

[salnys]

Cheers for the feedback.
Should the accesories wire be utilized? Sorry if that's a stupid question but i'm not very knowledgable about this. If only the constant, earth and accesories wire are used, should it turn on?
Maybe i should hook the accesories wire to the red ACC wire and the constant to the yellow Battery wire.
As far as earth wire goes, where would be a good spot to put it if i need to change the location.

[arrow224]

The black wire on the back of the head unit is and should run to the ground
The yellow wire (labelled battery) should be connected to the battery wire.
The Red wire (labelled ACC)

Doesn't this tell you something?
The red wire ACC should be hooked to the ACC (meaning accessories)
Yellow wire battery is your constant.
Black is your ground.

[ephect]

The black wire on the back of the head unit is and should run to the ground
The yellow wire (labelled battery) should be connected to the battery wire.
The Red wire (labelled ACC)

Doesn't this tell you something?
The red wire ACC should be hooked to the ACC (meaning accessories)
Yellow wire battery is your constant.
Black is your ground.

^^^ on the money ^^^

[camstatic]

Something that gets a lot of people with certain brands of source unit: When you go to power it up and nothing happens, always try pressing the power/source button on the unit.

[salnys]

Thanks guys for all your help.
I've tried everything and still can't get it to work. All except changing the earth but that is a bit beyond me. I guess i'll just have to run it downto some professional to cop a flogging.
Thanks anyway.

[r_i_d_a_h]

blow the radio fuse? check under the steering wheel.

[ephect]

or the fuse in the head unit itself