Orange Wire Hot? (at Alternator)

Ratrace Remedy

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Jun 3, 2007
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Should the orange wire at the alternator be hot?

Trying to diagnose a no-charge condition on my '84 Formula 350/260. Got the alt rebuilt (Mando) and still not charging (per the dash gauge and a volt meter at the battery) The smaller sense and excite wires I confirmed are connected correctly and the ground is good. With the engine off and the orange wire disconnected from the alt, I get no voltage at the wire. Per the wiring diagram, it looks like it heads to the starter, and there's a square fuse between the wire and the starter solenoid. I can see it, but can't get to it due to how low the motor sits in my boat, and the tight distance between the floor and the exhaust manifold. Should I have a constant 12v comng from the starter to the alt? If so, I suspect the fuse, but want to make sure before I go through the hassle of removing the manifold to change the fuse (I'll try a couple of long extensions first:))

thanks
 

Don S

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62,321
Re: Orange Wire Hot? (at Alternator)

Yes, you should have power on the orange wire going to the alternator, any time the battery switch is turned on. If you have a square fuse on the starter, that is something someone else put on. It was not OEM on an 84.
I think it was 2001 or later before they used those fuses
 

Ratrace Remedy

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Jun 3, 2007
Messages
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Re: Orange Wire Hot? (at Alternator)

Thanks Don, strange, my Saloc manual makes reference to the "90 amp fuse" in the wiring diagram at the back of the book. That's what prompted me to ask. The manual I have is identified as "Mercruiser Stern Drive '1964-1992"

I'll try to get the sucka off and test it.
 
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