I got a new deck (Pioneer DEH-P7500MP) installed 2 weeks ago which I ordered off the internet. About a week ago I had it cranking really loud (>>) and suddenly one of the left speakers started to crackle...so I immediately turned it down and it was fine. I turned on my car later that day and it was fine, but then I turned the deck off and put in a different CD and it never turned back on. I pressed the power button, eject button, etc. but nothing worked. I checked all the plugs in the back and the fuse but everything looks okay.

I talked to somebody about it and they told me it is probably a faulty CD Player. I was also told by the people who installed the deck that my wiring is very messy but I don't know exactly what they meant by that.

I am guessing it's the deck, but does anyone think they know why it would suddenly stop working like this?

The odds the deck went bad are pretty slim. It does happen but not often.

Messy wiring usually means someone else had done wiring in the past and did a sloppy job.

You said you checked the fuse. Did you check just at the fuse panel? There should also be a fuse in the harness behind the radio.

If you can, get a multimeter and check for 12v at the red and yellow wires. You should have power on both with the key on and only on red with the key off.

It is possible the wiring may have shorted out your deck. If that's the case have it fixed before you put in a replacement deck.