Re: 2nd Battery/Isolator Relay Switch
 

Well I thought everything was working right. I charged the battery and then had it summerized by the marina. I go to the lake for the first trip of the season and I show up and notice my boat on a charger. The marina says the battery is dead and they also charged it after summerizing it. They test the battery and it is good. My second battery for the radio reads 13.2V. All good there. Last year I added a single amplifier and no extra battery and had no problems. I add a second battery and isolator and now something is draining power. The radio will not turn on when the key is in the off position and the amp lights aren't on showing power either. So the remote turn on from the radio to the amps is wired right. No problem there. Turn the key to accessory or on and everything works like it should. I ran a wire from the isolator to the ignition fuse and tested it with a volt meter and I can here the isolator open when the key is in the on position and close when it is in the off/acc position so I think I am good there. No power from the ignition fuse when in off position like it is supposed to be. I am stumped. Can you please help me with some suggestions. I can't go on the water without some tunes (or I will have a dead battery if I sit too long). Thanks.

Re: 2nd Battery/Isolator Relay Switch
 

If both of your amplifiers are wired to the second battery and that battery is charged, you probably have a draw from somewhere else on the boat that coincidentally started at the same time that you were concentrating on the stereo. It sounds like the isolator is working like it should. Are you sure everything got turned off after you were done with the stereo work? A fan switch or bilge switch might have been on by accident. If not, I would start with the alternator or starter. They are the usual suspects of killing a battery, besides stereo systems. Do you know if you are still getting a draw on the first battery? If so the best thing to do is start disconnecting one circuit at a time until you don't have a draw. The circuit that you just disconnected is the culprit. It's time consuming, but start with the obvious ones like the stereo, acc, lights, ign.....etc.

One last thing. A Perko battery switch, to disconnect the batteries when the boat isn't in use, is always a good idea. A very small draw won't affect your day on the lake, but over a weeks time it can drain your battery.