Car Stereos: DECK INSTALLATION TROUBLE, sony cdx, blown fuse

Question
I am having alot of complications with installing my car audio deck sony cdx. At first it was installed, it started to play music fine until fitting it into the car deck space, the wires got pushed back and loose. So I tightened all the wires together while the key was in and when it turned on the deck itself was on, but there was no display of anything. Again I took the deck out and worked on tightening each wire but I left the keys in the ignition and used a metal tool to tighten the wires. As the tool came in contact with either the deck metal or the wire metal(yellow wire), a spark ignited. After giving up on my deck, I placed my old stock deck in but this time it would not play, but a hour earlier it did play. So I am wondering what is the cause of this and what I should do to get it fixed and if professional fixing is needed how much would the labor be?

Answer
Hi Kelvin,

You almost certainly have a blown fuse in the vehicle's fuse box, and it's likely that you have more than one.  In most vehicles, there are two fuses that supply power to the radio: one's for the constant power wire, and the other's for the key-switched power.  Often the circuits are shared with other power accessories in the vehicle, and they may not both be labeled as radio fuses.  So the best course is to check all the fuses in the vehicle, including any fuse box under the hood.

If you have a digital multimeter available, here's a method for quickly testing fuses using your meter's voltage function:

http://kzcarfi.blogspot.com/2008/08/testing-vehicle-fuses-with-multimeter.html

Hope this helps!

Brian