Isolated system but still need "ignition" on to wo

[Chexi]

Ok, I thought I had accomplished my goal of having an isolated battery for my audio system so I could turn my boat off, listen to tunes, and not worry about running down the cranking battery. However, yesterday I noticed that if I turned the ignition breaker / switch off my head unit, amps, and WS-420 all shut off. Each of my amps, head unit, and WS-420 are wired (power and ground) to a distribution block. The block is wired power to Blue Seas battery switch and ground to cranking battery (all my grounds are unified, including the 2 different use batteries). I also have the Blue Seas relay in there off the switch. So my power lines for the audio system should be isolated from the cranking system, the key, etc., but I did notice before that the audio would go off for a second when turning over the engine (and did not realize this was odd for some reason).

However, yesterday I realized that the audio would not work without the ignition breaker/switch in the on position. This is a problem because some motor somewhere runs when the ignition switch is on (just found this out). Whatever that motor is (have not yet identified it) probably shouldn't be running for hours on end with the boat not running, and it will also drain the cranking battery. So what gives? How do I correctly completely isolate the audio system? Do I need to "un-unify" the grounds between by 2 batteries and move all the audio grounds to the audio battery? I was told not to do this when setting up the system, but it is the only think I can think of that would cause this. Although, now that I think about it, the head unit was originally installed by a dealer and was originally installed with power from the normal cranking system. Perhaps there is a key-on wire connected like a remote on to the head unit that I can simply disconnect? If so, anyone know what color that line would be?

I have a 99 Air with GT-40. Head Unit is Clarion M425. Amps are Alpine. Also a WS-420 EQ with remote on wired into Head Unit remote on. I have included my current wiring diagram of how I set everything up (but not including the WS-420, which is also wired to the distribution block).

[harddock]

RE: Isolated system but still need "ignition" on t

just a thought. Do you have a fan on either one of your amps? It might just be the motor sound you are hearing>

[crowland]

RE: Isolated system but still need "ignition" on t

I am a little confused as to why you are running all of your amp power through the Blue Seas Switch - If you are trying to isolate you would just want that switch and relay between your 2 batteries? I would think you need to run ALL Stereo items directly to your deep cycle battery. I think your grounds are fine as long as you are going to the same place.

[crowland]

You are correct - Find that Remote Wire - If that is hooked to your starting battery that needs to be moved. Also here is a wiring diagram - I am not sure where that manual switch that you have should go, but I believe this is how you should hook up that Isolator - (sorry for the crude drawing)

[Chexi]

I did not have time to mess with the stereo today, but I am almost positive that the red power is tied into key hot on my head unit as this head unit was installed by a dealer who hooked everything to the cranking system. I will combine it with my yellow (which goes to my distro block and then to my audio battery) and see what happens.

Crowland, the blue seas system I have uses an isolator/combiner switch. It has 3 settings. First is off. Second is pure isolation (so the cranking system is a closed circuit and the audio system is a second, separate closed circuit). Third is combined (if your cranking will not turn over your boat, it can combine the audio battery to give your engine extra amps). That is why they are both hooked into that switch.

I sent an earlier power diagram to Blue Seas and they corrected one thing on it. The result is the diagram I posted.

I do not have a fan on either of my amps, so I don't think that is what I am hearing. The WS-420 apparently often runs into this issue (or at least used to a year ago when it first came out). After I fix the red wire issue next weekend, then I will re-test. I may end up having to add a noise filter into the mix.

[Chexi]

Spot on Crowland. The red key-hot wire was exactly it. I cut it, taped it off, and tapped the head unit side into my yellow always hot power wire. Works perfectly. It also eliminated about 95% of the noise I was getting in my speakers when I did it! Hooray!