JVC KD-G340 Power Problem

Question

I just bought a new JVC receiver for my truck to replace the factory one that had stopped working.

When I hook up the yellow wire (unit is grounded, red wires connected), the unit will start up, buzz a second or two (::think CD ejecting sound::), then go off. Pushing the I/O doesn't do anything, but if I hit the eject button, the unit will try to eject, then go back off.

Any ideas?