Car Stereos: audio system blew fuse?, fusible link wires, mercury cougar

Question
i have an 89 mercury cougar and i just installed a new kenwood deck as well as 4 new kenwood 240 watt speakers.  i turned the music all the way up and then the music shut off, along with all other accessories and the lights on the display for my speedometer.  i have checked many of the fuses and none of them are blown, i even tried replacing them anyway just to make sure and still nothing.  Do you know what could be wrong and what i can do to fix it?

Answer
Kevin,  Along with the fuses located under the dash, which should all be checked; there are fuses under the hood and fusible links under the hood.  These other fuses and links "usually" do not blow from overpowering them.  Usually, they blow from shorts to the main wiring system.  Perhaps, one blew from the radio being cranked up, or there is some short somewhere which caused the problem.  The fuseblock under the hood has larger fuses that can all be checked and replaced as needed.  The fusible links are usually located in the wire harness coming out of the firewall.  They are 4-6 inch wires that are spliced into the normal wires.  When A short occurs, the fusible link wires meltdown quickly to keep the rest of the wire from being compromised.  You can tell when one is melted down, because it looks melted and turns black.  Whether you find a bad fuse under the hood or a bad fusible link, just replacing it will probably not solve the problem.  There is probably a short somewhere that is causing the problem.  I would have someone experienced in auto repair take a look at it and determine what the problem is.  Good Luck, Scott