battery isolator

[lynnboy021]

my boat already have one installed but i want to know where on the alt i install the input wire.. i have it installed like this

 

[Boatist]

Re: battery isolator

Need more information.
Is this boat an I/O or an Outboard?

Your diagram looks ok but to small for me to read.
The red wire to the isolator common then the two isolator outputs to you switch and batteries look ok. Comm from your switch to run every thing on the boat is ok also.

As shown then each battery will be .7 volts lower than your alternator output. So if your alternator puts out 14.8 volts the batteries will get 14.1 volts.

My question is what is the red wire off the top of the alternator for?

If this is an outboard I would not recomend a battery isolator.

 

[lynnboy021]

Re: battery isolator

sorry its for a 1988 omc 5.7 and i have a 3 wire alt

 

[lynnboy021]

Re: battery isolator

how about this one View attachment 91358

 

[Boatist]

Re: battery isolator

If it is a 3 wire alternator then the heavy RED or Orange wire should go to tha isolator Common. This wire should be 8 or 10 ga.
The (F) field wire should go to the voltage regulator output.
The (R) relay wire goes back to the ingition switchor relay.
Normaly no need to change the Field wire or Relay wire when installing a isolator.

All you need to do is take the altenator ouput to the isolator common then that battery one output to battery 1 and battery 2 output to battery 2.

Usually the wire from the alternator output will go on the hot side of the starter solenoid. So you can take the wire off of the alternator and move to isolator battery 1. Then use a wire size larger from alternator it isolator common. Hook up battery 2 to isolator 2 and your set to go. The other wires on the Alternator do not need to be changed. Of course do it all with batteries disconected.

Are you having a problem with it the ways you have wired?

 

[lynnboy021]

Re: battery isolator

um i dont know yet cuz the wire going from alt to isolator was not pluged in.

 

[Boatist]

Re: battery isolator

If you ran the motor without the wire to from the alternator to the isolator or a battery then the alternator likely blew the output diodes from way to high a voltage.

With the field wire hooked up and no battery load the output diodes normally blow in less than a second.

So if it does not work take the alternator in to an auto shop and have it tested.