blew a fuse?

[SiR JDM]

hey guys i tried to install my headunit and something went wrong..

there was power.. enough to eject/inject the cd but thats it.. no display etc..

i took it to a friends place with a multimetre n that..
n he checked al my wires, n for some reason my constant is only giving out 3volts while engine is off and 12v when it on.. my friend said this is not right and i have a short somewhere or a blown fuse

I also noticed my clock near my cluster (EG civic hatch btw) went off and isn't worknig at the moment.. after the deck? so it seems somethin has gone wrong?

anyideas guys :? ? i really needa fix this up

[**PIMPIN**ACCORD]

Some symptoms sounds like a fuse and some dont. If you blew a fuse you shouldnt be getting any constant power at all :S. I blew a fuse in my accord and the clock and head unit wouldnt work...Check your fuses and make sure they are all in tact