Trouble brewing with alternator?

[Jono]

I have a real basic boat ('96 SS), with a temporarily real basic setup - no amps/subs, no auto ballast. Those items are on the to do list right now, but I have to lay down the electrical framework first and make sure I'm not going to have any amp draw problems. Onto the problem-
The deck is powering 4 interior speakers and wired to the dash. The yellow lead is coming off the master ignition switch. Cranking the volume only moderately on this gutless system is enough to trip something and shut it down. The pulse (not thump) of the base causes the voltmeter to bounce in time. I thought this should only happen if you had a party cove stereo.
I've got a second battery hooked up to a perco sitting there doing nothing but being a backup. I know when the accessories add up I wire them straight to the battery. But do I wire to a distribution block first? Otherwise wouldn't I have a birds nest of wires from the amps and ballast pumps on the battery?
I plan on replacing the perco with a sure power 1314. Since that would put my alternator in kind of an autopilot mode, as opposed to letting the shore charger take the load off, I'm wondering if I should be looking at the alternator given the symptoms I have. BTW, the stereo upgrade will probably stop short of tower speakers and just have an amp powering the sub and interiors.

Thanks for any advice

[Grant_West]

I dont know what to tell you as far as finding your problem. Make sure all the connections are solid and tight, If they are loose they can cause resistance and extra load. But what I can tell you is. One battery should have enough power to keep your system playing with out tripping anything. Your Deck draws very little power. Your Amps(if you have them) should be connected directly to the Pos and Neg of the battery. Most likely your head unit is either bad or going bad OR you dont have a good connection somewhere