Twin Engines, Two Batteries; Port Engine Dies

Electrical and electronic topics for small boats
hungrycruiser
Posts: 1
Joined: Thu Oct 06, 2022 7:30 pm

Twin Engines, Two Batteries; Port Engine Dies

Postby hungrycruiser » Thu Oct 06, 2022 7:38 pm

On a Boston Whaler 305 CONQUEST boat with twin engines, everything works well when [both battery switches involved in the distribution of power from two battery banks] are set to the BOTH position.

When the Port battery switch is set to the 1 position and the Starboard battery switch is set to the 2 position, then the Port engine almost immediately dies.

Give me some explanations of the cause.

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: Twin Engines, Two Batteries; Port Engine Dies

Postby jimh » Fri Oct 07, 2022 5:27 pm

GENERAL CASE: In any electrical circuit where a battery is the source of electrical power, if there is an electrical problem related to lack of or absence of electrical power, the first circuit element to test is the battery.

SPECIFIC CASE: Check Battery 1.

GENERAL CASE: If there is a switch mechanism involved in the distribution of electrical power, and there is an unexpected absence of electrical power in a circuit downstream of the switch, check the switch.

SPECIFIC CASE: Check the Port battery switch.