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About alternator and positive wire BF75

A

alchage

New member
Hello everyone.

First of all, say hello to everyone, as I am new to the forum.

The second, I want to apologize for my English, I have to use Google translate.

I tell you my doubt. I have a Honda BF75 and two batteries that are currently attached. I want to put a separator diode, the problem is I don't know where the alternator is and where the positive wire of the alternator is.

Hope someone can help me.

Thank you very much.
 
Welcome!
Diode plan drops the voltage passing through it by nearly a full volt. For that reason, many consider it a poor plan. Much better is a heavy duty manual on-off-both switch. Bonus is they are much easier to figure out how to connect.
 
Understood, but there are different types, the best being a "latching relay" that uses no power once energized to the on or off position. These are frequently used on recreational vehicles.

Diode type isolaters have pretty much gone out of favor for their lack off efficiency (due to the voltage drop caused by a diode in the circuit). The second issue regarding an outboard, will be how to install it given the way an outboard is wired.
 
indeed, the wiring is the problem. I need to find the positive wire coming out of the alternator / stator. I take that cable to the isolator, and from there a battery to the engine and another to the boat
 
Not for the faint of heart. I hesitate to even try to provide guidance. Clearly you're messing with some really expensive parts. That in mind-

Look at the rectifier wiring. You'll see 3 wires coming from the alternator field windings (A/C). In addition to those 3 wires you'll likely find one wire leading to the fuse block. That's the wire you're looking for.

From there I'm going to claim ignorance, with no further help. You already know what I think of your plan....
 
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I have gotten the electrical diagram. Can someone tell me which cable I should take to the isolator? thank you
 

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Hi,

First off, I've never done what you are considering AND I don't have any experience with the Honda alternator charging systems.

Having given you the disclaimer I'll continue.

I think this diagram is flawed. I'll explain:

Your trim switches should have powe all the time, right?
And the ON signal to the regulator/rectifier should be SWITCHED through the combination switch.

But this diagram shows the WHITE with BLACK DASHES wire that feed both trim center (positive) terminals are connected in parallel with the regulator "on" terminal.

I don't think that is correct.

Additionally, there is NO depiction of power, for switching, going from battery to the ignition switch.

Unless I'm missing something here, I'm not sure I would depend on this diagram to accurately assess this system.

Placing diodes in the wrong portion of the charge system could result in uncontrolled volts and component damage which, I'm sure, you probably already know.

Measure twice, cut once as they say in carpentry.

Good luck with your project.
 
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