Car Stereos: am i a dummy?, using a digital multimeter, fuse boxes

Question
Hi Brian,
Today i bought a new pioneer deck, so i pulled out my old one. Jumping ahead and past the most important part... disconnecting my battery. i went on with installation and plugged in the speaker wire cord and the deck got power. then i pulled in my amp and then the power hit the harness and sparked, then my deck turned off and now does not work...the fuse on the back of the deck isnt blown either. am i out 200 bucks or is there other fuses that may have blown?
Thx, Tyler

Answer
Hi Tyler,

It's highly unlikely that you damaged your new head unit.  I think you just have a blown fuse in one of the vehicle's fuse boxes.  In most vehicles, there are at least two fuses that supply power to the head unit: one fuse for constant power, and the other for key-switched power.  The constant power fuse, in particular, is often blown during head unit installations.  

Finding the fuse can be a little tricky.  If you have your owner's manual, you can look for the "radio battery" or "radio memory" fuse; but often the fuse is shared with other constant power circuits, and not labeled as a radio fuse at all.  You might check your other vehicle accessories, particularly the dome lights, cigarette lighter, and horn.  If one of these isn't working, that might help you find the blown fuse.  

If you're having trouble, here's a guide to checking your vehicle's fuses using a digital multimeter:

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

Remember to check all your fuse boxes.  In some vehicles, the radio memory fuse is located in a fuse box in the engine compartment.  Also, be sure all your new wiring is fully insulated before you replace the fuse, or you'll just end up blowing it again.

Hope this helps!

Brian