Audio Systems: Fuse keeps blowing, mercury sable, metal chassis

Question
I have a 1996 Mercury Sable with OEM Radio that is not working. I replaced the fuse under the hood and it keeps blowing out. Any insight??  Thanks

Answer
Fuses go because they experienced too much current.  This means there is a short circuit somewhere along the line:  

-  Wires from battery to the radio unit.
-  Radio short inside (requires service or troubleshooting)
-  Wiring from the radio to the speakers (such as a pinched insulation section that is causing the grounding problem to the metal chassis).
-  Shorted voice coil in one or more of the speakers.

All are possibilities.  Do you know how to troubleshoot each of those conditions? If not, you should have it looked at by one who does, such as a repair shop or trained electronics tech.

Hope this helps.  Come back with follow up if you have more questions.