Radio constant 12v issue

Hi everyone,
I recently picked up a new radio and speakers. I plugged in the radio to a wire harness. The radio stated up fine and i connected it to one speaker just to test it.
Then i pulled the rear and front speakers removed all old speaker wire and ran heaver gauge wire throughout the car.
I hooked all speaker up plug in the radio and i get nothing. The radio does not power on.

First thing i did was check the 2 fuses behind the radio. 5 amp for the 12v accessory (green/white) and 1amp for the constant 12v(purple). I replaced the fuses with new ones.
Still nothing.
I checked the voltage with the multimeter at the inline fuse connectors. The accessory gets a solid 12V but the constant jumps around in the MV range and i believe this is the problem.

The trouble is that these two wire follow back just go into the main wiring harness with all the other wires.

How can i track this purple wire down the line to find the problem?
Also why do you think it was working originally? I did pull a lot of wire and cut a bunch of the old speaker wire out but i don't see how that would mess that up.
Any help on this would be really appreciated. i haven't had music in my car for 5 years and running that wire wasn't too fun. : )

The 1amp fuse (purple wire) is fed by fuse #17...maybe you poped it in the process?

Do yourself a favor and run a new 12v wire from the harness. You can get purple wire at Napa. I had the same problem and this is how I fixed it.

I thought that might be the next course of action.
Where do i run the wire to?
I was thinking of through the center console back to the fuse box(#17)?
does this sound right or should i take it somewhere else.

...tried looking at the wiring diagram but cant really figure it out.

You might get lucky doing that but it would be better to find the problem IMO especially since the lighter and factory clock (if installed) are the only other things on the circuit after fuse #17...Odds are high that the purple wire itself is OK and easy enough to check. More likely a bad connection.
You might try:
Pull fuse 17 and check the plug for corrosion, weak tension for fuse blades, and that the Brown wire terminal has a solid 12V. (I'd use a test light if possible instead of a meter here since it puts some load on the circuit where a meter doesn't.) If that shows good, replace the fuse and check the purple wire at the lighter, clock, branch splices between them along the way, the 1 amp fuse holder and finally at the radio. Don't forget wiggle tests in case it is intermittent and that you have to have a good ground for the radio.