Need stereo help

[jacques2727]

Hi guys,
Have a stereo issue and don't know where to go for help, hopefully somebody here may have a suggestion. Out of the blue over the winter, my head unit stopped working (clarion cmd4a). I confirmed power from the ignition, and ground seems fine so I thought it was the head unit. Took it to the shop where it tested fine. Put it back in the boat and nothing. Like I say, I've confirmed 12 volts power at the head unit when I turn the key, and I even re ran the ground just to be sure. Amps all have power to them but nothing turns on because without the head unit there is nothing to tell them to turn on. I'm really stuck here does anybody have any ideas? Thanks in advance.

[chpthril]

Check for 12V on the yellow wire. Should be a constant.

[jacques2727]

Thanks for the reply. Getting constant 1v to the yellow wire. The red power wire jumps to 12 volts when we turn on the ignition. So I should have 12 volts all the time to the yellow? And where do you think the problem would lie if this is the case?
Thanks again!

[chpthril]

Honestly, I cant remember where tige originated the head unit yellow on an 07. My gut says its run to one of the amps, the largest if theres two, and piggybacks to the amp's power power cables. This is what I would regardless. Likely faster then tracing the wire around the boat. Just use an inline fuse at the amp's power cable.