New CD Instalation

I was switching my current CD player to a mp3 player, in a car I just got (Doubt it matters... but incase it does, Mazda MX-3, 93) It had a wire harness in it, So it was a pretty basic, simple install. Although I did crosscheck the wires in my new Mp3 players instalation instructions, against the Diagram I found online for my car.

I ran across one problem - The constant 12V, doesn't work. I got my Mp3 player going by crossing over the ACC power into the yellow wire... but as you know, that doesnt save any of my information (IE: last song I was on/Radio presets) It looks like my old CD player...was installed this way also. I'm pretty sure it saved the current place in a song though... however I had the car for 2 days before I upgraded...so I'm not sure.

I have a Volt meter, And the yellow wire (12V constant) Has no power in it at all. The red Wire (ACC) Has the correct voltage. I checked the fusebox... and the fuse did not look blown. I took the fuse out of my windshield wipers, (Same voltage) Put it in...and it didn't work still.

Am I going to have to install a new wire into the fusebox? I'm not very knowledgable about cars... however I do have electronic experience. I'm tempted to cut open the 12V constant wire... see if it has power without the harness on...and eventually I think I'll have to do that. Would the easiest way be to install a new wire and lead it to the CD player? If it is...anyone have any webpages with instructions? I only know how to use a volt meter very basically... not sure if I know how to use it to find a constant 12V...

Any help appreciated, Thanks :)

Check and see if you have a second fuse box under the hood and see if there is a wire labeled memory or back up. If not run a wire directly to the battery with a fuse in line as close to the battery as possible.

-------------
There is no such thing as free installation!

I'm about to undo the whole CD system, And check each wire to see if it's got 12V or not. I got my uncle to install it since I've never installed one before... but looks like he didn't know exatly what he was doing ;) don't think he even unhooked the Car battery... Could he have fried something there? I'll look under the hood for a second fusebox first, though.

The CD player that was in it... the yellow wire has a fuse attached to it. I'm not very good at electronics... so would that fuse make a difference? I don't think so if the wire doesnt read any power at all... I'll look into if theirs another fuse box under the hood... then I'll re-check all the wires for a 12V... If that dont work... I guess I'll have to try to run the wire from the battery.

As for that... Seems a little complicated. What do I do... just attach a wire to the batter (With a fuse along the wire) And run it through the dashboard or something? Any instructions/guides online or anything?... I almost feel like just going to an installer... but in Canada it costs $100... and paying $100 just to get a simple wire put in, seems like a waste. I've fixed electronic stuff before... know a lot about wiring/proper wiring.... I'm usually doing it with computers/Electronics. Pretty confident I can do it without frying something, just unsure of which fuse/wiretype to get...and how I'd get it from the battery :\ wouldn't it be easier to go from the fusebox?

Just went under the hood, and found a Wire connected to the battery... The wire led to a fuse, and it was blown. I'm presuming this was my constant 12V.... I went and changed the fuse, Now the yellow wire shows as "1.5" volts on the voltmeter.... is something else messed up? running out of ideas on what to check....