What Is the Correct Way to Connect Two Different Sized Wires?


I replaced a 24V air-ventilation fan in my engine room. The old fan was an Attwood 4" (24v, 1.9A), the new one is a Rule 4" (24v, 2.4A). The boat wiring runs from a dedicated circuit breaker on the switch panel, to a on/off switch at the helm to the fan. My vessel's wiring is 10 gage, but the new Rule fan is only 14 gage. I installed it using a yellow butt-connector, paying attention to making good crimps. Is this the right way to connect two different wire sizes? - Brad


Thanks for the question, this is a great one.  When doing butt connections it is important to make good connections as you suggested but also to make sure they have heat shrink to prevent the ingress of water to the wire which would cause corrosion.  Here is a video on doing bilge connections – you’ll notice Jeff used a yellow butt connector with the reduced side on one end for the smaller gauge wire. An alternative would be to use a terminal strip if the connection is in a safe dry area.  https://www.youtube.com/watch?v=_gnOj0J7BWs