Audio Systems: Cd player wiring, jvc cd player, customer change

Question
Hi I'm wiring a Jvc Cd player I purchased new last year into a 85 K10 pickup. I took out the old radio and used the old wiring it seemed to be good still. I can get power to the Cd player but I cant seem to get sound to the speakers ive rewired it several times and checked all my fuses but i cant seem to find any reason why the speakers wouldnt work. Ive replaced the speakers in the back but still im not getting anything hopefully you can help me but thanks for your time.

Answer
HI Jim,
could it be you havn't got a 12v signal to an amp from the head unit?

Failing that,,,,, scratch head... follow my idiots guide to wiring a head unit and it should all become cystal clear,  I hope.

Peter

Check out the car is NOT the problem first though, had many a customer change the radio to no avail when it was a simple fault on the car.

You will need a test meter set to 20vdc or a 12v lamp or 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)

The third, usually top, block is for accessories such as cd changers