Brand new Clarion CZ100, 20 minutes and it fried?

I bought a new Clarion CZ100 from Amazon, hooked it up in my 93 Cherokee using a Scosche wiring harness/plug thingie from Walmart. It worked and sounded great...... until...... I was sitting in the Jeep playing around with the EQ settings, trying to get it to sound as best I could. About 20 minutes later, pfffffffft. Everything went to crap and the speakers started cracking and popping. I could still hear the music, barely, but it was all distorted and crunchy. At first I thought I blew a speaker or two...... but all 4 speakers at exactly the same time? No way. My speakers are nothing fancy, just some Soundstorm 6.5" 3-ways in the doors. They claim to be 350 watts apiece, probably nowhere near that in the real world, but the head unit only puts out 17 watts per channel RMS. Anyhow, I pulled the stereo out of the dash and HOLY CRAP the heat sink was hotter than the hubs of hell. I coulda lit a cigar off that sucker, WAY too hot to touch. It took almost an hour for it to cool down enough that I felt ok wrapping it back in the plastic bag it came in.

I checked and double checked everything to make sure I hooked it up right, and as far as I can tell, all is well. So did I just get a bad deck? What could have caused this thing to fry like that? I'm going to buy another stereo, I just wanna make sure it doesn't happen again to the new one because of something I have may done wrong. Thanks for any help!

 

Well obviously its going back. But then I plan to buy another deck, so does anyone have any idea (other than "bad head unit") what may have caused this to happen?

 

No, its the standard am/fm cd player that came in the 1993 Grand Cherokee Laredo, which worked just fine for 18 years. I pulled it out and hooked up the Clarion and didn't even get a half hour.