Problem with Mastercraft battery isolator

A customer of mine has a 2004 X-Star that I've done some work on over the past few years. The boat originally had 1 battery, but 3 years ago, I added a second battery. I think it's tied to the Perko switch, but can't remember. It could be wired in parrallel with the other battery, but I won't have the boat until tomorrow to verify this. I do know that all the amps are wired directly to the Stinger SP1700. A couple weekends ago, an amplifier was added. The boat currently has 2 Syn6's and no other amps. After taking the boat out a few times since the last install, the battery isolator burned up. It's visibly charred, so I'm gonna assume that no current is passing through. The SP1700 has it's own 6A charger wired directly to it, and is charging when the boat is on the trailer. The owner is not mechanically inclined and doesn't know how to troubleshoot anything, so until the boat is in my possession, that's all i can say.

What's the point of this isolator? can it just be removed? All the boats I've worked on have had 1/0 directly to the switch from the alternator, then 1/0 to each battery.

I go to look at the boat at 0700 Thursday morning and can have more information, any help is appreciated.

jonyb,
Give me a call and we'll talk about it. I can fill in all the blanks a give you a few options.

David
Earmark Marine

Thanks David, haven't been on here since last Thursday afternoon.

I ended up dumping the isolator. I ran a 1/0 from the alternator to the switch. The isolator had a lot of corrosion on the input side from the alternator. The compartment where this was all mounted was soaking wet also. When you don't take care of your things, this is what happens. Also, both batteries showed 5.5V. The battery switch had been left in the "all" position at all times and with the isolator smoked there was no charging done at all, other then from the 6A Stinger charger that was only intended for the SP1700 battery.