Battery replacement and issues with all electronics on boat

[Jeffk]

Hi All,
I have a 2011 Supra 242 and just replaced the old batteries because they did not seem to hold a charge anymore. I put two new Interstate deep cycle batteries in today and the motor cranks up great but nothing else works on the boat other than the screen? Voltage shows about 12 volt which is a little low so we ran the boat for a while on the lake but no increase and still..... no radio, lights, blower, etc. The VSR Voltage Sensitivity relay module light is on red but even when I plug the batteries into dock power none of the things work? Any ideas what might be causing it, hoping to have big time with kids at Smith Mountain Lake this weekend.

Thanks,
Jeff

[Wylietunes]

I would look for a rogue battery cable that left off. Something like a 4 of 6 gauge that feeds the helm BUS.

[Jeffk]

Thanks i did go back out and realize there was a cable that was not hooked up. I hooked it up and changed one other cable and still none of the components are working except the screen. Does anyone know if there is a good place to view the correct wiring of the battery to make sure i have it all hooked up right?

[CJD]

I've been looking for a wiring diagram since I bought the boat. I haven't had any luck. though.

One possibility...that I have managed to do before, is to hook both the positive and negative cables for the accessories to the same post on the battery. Fortunately, this does not hurt anything. This is easy to do, as many times there is no color difference between the pos and neg accessory cables. You have to follow the wires to the first stop and see if it should be pos or neg. Just use care not to reverse the polarity of the accessory cables, as that WILL damage some items.

Another possiblity, since you have 2 batteries, is that the common ground between the batteries may have been left off. When the batteries are out, this wire is free at both ends, so easy to set aside and forget. If accessories are hooked up with the pos feed on one and the neg feed on the second battery, there is no completion of the circuit.