Head unit to amp problem

[Barefutin]

This setup is in a boat. Have a JL Audio CMD5 head unit that has front and rear rca outputs. Front outputs goes to a Kicker kx800.5 amp that powers 4 cabin speakers plus sub. Rear outputs goes to a JL Audio M2150 amp that powers 2 tower speakers. All was working fine, used fader to take sound out of cabin. When fading sound back to cabin, the tower speakers quit emitting sound. A side note is the tower speakers can emit sound but it is very faint. Ear has to be in in front of speaker to hear. Thinking amp may have gone bad, I tested it by connecting iPhone to amp via rca connections. Music played as should and sound came from tower speakers. Thinking bad rca cable fromhead unit to amp. Test continuity and that tested ok, but went ahead and installed a known working set of cables. Still no sound. Now thinks bad rear head unit outputs. Switched the rca cables so that front signal goes to tower speakers and rear signal goes to cabin, thinking if bad rear head unit outputs, the cabin speakers would have no sound and tower speakers would. This wasn’t the case. Still no sound coming from tower and sound came from cabin speakers, so now this tells me the outputs from head unit are good. But at a loss as to why any signal that goes to JL amp from head unit, doesn’t get to it. At least that is my thinking. Any help will be appreciated.

Click to read more...