Simple Battery Isolator Wiring Diagram

When it comes to boat system wiring, having a clear understanding of simple battery isolator wiring diagrams is crucial. A good primer for beginners is the '1-2-B Switch' by Maine Sail, which brings together various aspects of this subject. In this article, we'll explore the basics of battery isolator wiring and provide helpful suggestions for replacement and wiring.

A typical setup involves separate cables from the alternator to the starter and house batteries, with the starter and house batteries connected to pins 1 and 2 respectively. However, without a manual specific to your Guest model or reference to someone wiring up the isolator in this fashion, it can be challenging to find the right information.

In the case of a battery isolator failure after 14 years, troubleshooting is essential. For instance, when running the motor at around 2000 rpm and turning off the solar charger/MPPT controller, you may notice a voltage reading of 14.28VDC on pin 1 but only 12.38VDC on the labelled A pin. If there's no cable attached to the third pin numbered 2, it's likely that the issue lies with the battery isolator.

To identify the problem, it's essential to understand how the system is wired. On top of the battery isolator, the cable from the starter motor/starter battery goes to pin 1. Meanwhile, the house cable connects to the labelled A pin. The + side of the switch is connected to the starter battery itself, and a cable runs from this side to the battery isolator.

However, it's important to note that there is no direct cable from the alternator to the battery isolator. Instead, the cable from the alternator goes to the starter motor, then to the starter battery on/off switch. The battery isolator has three pins on top: 1, A, and 2.

In your case, with a Bogart 2007 Hunter 45CC equipped with a generator, you have one AGM starter battery that starts both the motor and the generator, as well as three AGM house batteries. When running the motor, the house batteries are not charging, which is likely due to an issue with the battery isolator.

To resolve this problem, it's recommended that you replace the failed battery isolator with a similar capacity part. If you're unsure about the wiring process or need further guidance, consider consulting with an expert in boat system wiring.

By understanding simple battery isolator wiring diagrams and following proper troubleshooting procedures, you can ensure your boat's electrical system runs smoothly and efficiently. Remember to always prioritize safety when working with electrical systems, and don't hesitate to seek help if needed.

Simple battery isolator wiring diagram