Audio Systems: No sound from cd player, fuse box, pioneer deh

Question
Hi, I just tested my Pioneer DEH-P33, and I have no sound. Also when I installed it I found that there was no constant 12V wire for my car. I ran a piece of scrap wire to the + on the battery and it powered right up. I plan to do something with that though. No sound though. CDs play and the tuner picks up on the radio stations, I can see the signal indicator turn on.

I was only testing it out because I got it for from my bro for 25$ and I don't have the wire harness yet but I put the wires in the proper slot in the harness and Voila!


Answer
There must have BEEN a constant 12v (+30) for your car radio, the fact it is dead is another matter and one that should be resolved before continuing.
Some older cars do not have an accessory or ignition wire though and one has to wire the two required lives (+30 & +15) together so the radio is constantly live and relies on the on/off switch only to turn it off or run a wire from ACC (+15) on the fuse box OUTPUT.

I attach below the standard procedure for installing a radio into an unknown harness, I suggest you go though it step by step and if you follow the text your radio WILL work again, it has to, unless it’s knackered of course.

You will need a test meter set to 20vdc or a 12v lamp on two wires or 12v test probe.

I run this test when working on a car where a previous owner has ripped the connectors out of a used car and the new owner is in the same boat as you so it cover all the basics and should sort you out. So armed with your 12v probe or test meter, some paper, masking tape and a felt tip pen, here ya go!

Speaker wires. (non-amplified) these are tested with a AA battery across a pair of wires and you will here a 'pop' from the speaker,

These are normally twisted together in pairs (if you are lucky) and usually in a loom of their own before going of to the four corners of the car and are the same colour for each pair but one with a colour trace on, i.e. blue and blue/white, green and green/white.
Label it (e.g. left rear), continue until all four pairs are identified and labelled.

Earth one side of your meter or tester to a metal part of the car, probe each wire until you have a wire that is live all the time with the ignition OFF, label this ‘+30’.
Switch on ignition and redo test until you find another previously dead wire now live, this is ‘+15’.
Switch off ignition and switch on the side / park lights, repeat test until you find a third live, label this ‘lights’. Switch off the lights
You should now have two or three left. One will be earth, (usually black or brown); one could be to an amp and or electric ariel (usually blue or blue white) and one for phone mute if fitted. Clip tester to +30 and probe one of the remaining wires, if you have an electric ariel it will go up. Connect your DIN plug to the correct wires and jobs a good un’.

DIN connections  are.
Speakers

Right rear -,  right front -,   left front -,  left rear-,
Right rear +, Right front +, left front +, left rear +

Power block viewed from cable side

Phone mute (white),/   n/c, /      ariel & amp (blue), /ignition (red)

N/c, / 12vlive, (yellow or orange), / lights, (various colours),/ negative (black)