Car Stereos: Engine noise, engine whine, aftermarket radio

Question
I replaced the factory deck in my 1998 lincoln navigator with an aftermarket radio and have tremendous engine noise and can't figure out the problem. Any suggestions on how I can get rid of it.

Answer
Hi Joseph,

If all you've done is replace the head unit and there wasn't noise before, then the likely scenario is an incomplete connection somewhere.  Likely one to do with power.  Either the 12v constant, 12v switched, or ground wire aren't making a clean enough connection and so you're getting engine whine.

You might want to try disconnecting the ground wire from the harness, and connecting it directly to the chassis somewhere that is unpainted metal (somewhere on the firewall would be ideal).  That should clear up your issues.

Justin