so this is how my set up is wired.
dual batteries linked in a series on position 1 of the Perko switch, single battery on position 2 of Perko. 1 of the dual batteries is for cranking the boat, the other runs lights and speakers. the grounds for the amps are grounded to the non cranking battery in the series. i have checked all the grounds going from the battery to the amps, as well as the ground going from the HU. every thing has been re-grounded and appears to be soild. when i turn the boat on (just the batterys) the speakers make a faint "pop pop pop" and when i try to turn the ignition over there is a pretty loud "whine." any thoughts on something i might have missed?
there was a little interference at the end of last year, but nothing like this. the headunit is brand new clarion cmd6
recent upgrades: all new interior speakers, LED speaker rings, transom lights, 3 new batteries, 4 new tower speakers
Process of elimination is your best bet. Did you do the install or someone else? Unplug the RCAs first and see if the noise goes away ( it probably will). Next hook the RCAs back up and unhook all of your lights. Sometimes noise comes from other accessories, gauges, etc. that are hooked in with audio equipment. You can also try running a temporary test ground for the head unit. Does everything hook straight to the second battery or did you hook lights or other accessories anywhere else for instance the remote out of the radio, sharing turn on switches or anything else? Are the RCAs new or old? It might take some time if you added all the items at once.
Just had to deal with this problem after I installed my speaker lights. With me I have a controller for my LED's and all I had to do was run a dedicated larger ground wire from my controller to my battery ground. Anywhere your boat power wires are running parallel with your speaker or RCA wires there is a possibility of interference . Did you run the power wires for the speaker lights next to the speaker or RCA wires ? that may be the issue...
got it solved guys! thanks for the input. the only issuse was a faulty ground coming out of the HU. after 7 hours and checking everything like 4 times over i just re-grounded the HU and works perfect. always seems to be the smallest thing that causes the biggest problem!