whisper quite output from head unit...

[saucy5000]

So I had an Alpine head unit, but it got stolen last night. Today I put in an old eclipse head unit that I had lying around and everything works fine except there is hardly any volume.

you can't hear it at all until you turn it up to the max level and then the sound level is that of a whisper.

Any ideas? I double checked every wire and I'm kind of thinking the deck is bad, but it worked fine last time it was in a vehicle (which was 4 years ago) so I don't know.