What are these screws?

2fs2ns

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'87 Mercury 35hp.

Does anyone know what these two screws are? Look like postive/negative terminals of some sort...

mercwires_web1.jpg
 

Laddies

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Re: What are these screws?

Those are the screws for the temp senser, 1 is grd. and the other is the lead wire to the control box
 

2fs2ns

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Re: What are these screws?

Thank you! So that ground wire, it's melted in a few places going to the battery ground. In the case and out by the battery.
wiremelt_web.jpg


In the same wire sheating (coming out the harness) with the black wire is a red wire, going to the screw below, but it's not connected to anything out by the battery. Should it be connected to the + terminal on the battery?
wires_web.jpg


Also, what/where is the control box?

Thank you so much!

Dan
 

Laddies

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Re: What are these screws?

I know what the first wires you show were and the control box I'm talking about is the shift box there is a warning horn in it. I can't tell what the other wires are. If you want I can up load a wiring diagram for you. It will take a while as I am on dial up
 

2fs2ns

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Re: What are these screws?

Well that black wire on the upper screw is the same one in all the pictures, it goes from the upper screw to that bare wire on the battery end.

If you have a diagram I'd love to see it. You could post it or email it, whatever would be easier to do.

2fs2ns@gmail.com
 

2fs2ns

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Re: What are these screws?

Thanks, so where do you think those temp sensor wires are on this diagram?

Are all the two red and one yellow wires going to other points to monitor temperatures elsewhere on the motor?
 

Laddies

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Re: What are these screws?

Duh. sorry about that I checked on the year but didn't really look at the diagram and when I rechecked I don't have one for a 2 cyl. engine with a warning system.
 

2fs2ns

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Re: What are these screws?

After stripping some of the wire off off the sleeve on the battery end of things, it turns out there's a purple wire in that same sleeve.

On the engine side I can now see it loops around to the front of the powerhead somewhere, I need to trace it....
 

Laddies

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Re: What are these screws?

The purple wire is a switched 12v lead from the ign. switch and is normally the power wire for the auto blend system and is taped back at the engine. You need to buy a OEM manual or goto the nearest dealer and get a photo copy of your wire system.
 

2fs2ns

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Re: What are these screws?

I actually have a Clymer manual, but i can't find anything in it about the temp sensors/warning horn's.
 

Laddies

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Re: What are these screws?

The only mercury engine dia. I have with the warning system for heat and auto blend is for a 45HP the warning system wiring is the same and the color codes are the same but it's a 4 cyl engine would that help you
 

2fs2ns

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Re: What are these screws?

hehe, no I look at the outboard and I see that it's a "Mecury 35 Oil Injected". But the guy I bought it from has been mixing gas the last two years when he's owned it.

All the gauges on the console work except for the water PSI gauge.
 

Laddies

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Re: What are these screws?

He was probably mixing oil because most auto blends have either failed or been removed by now. HeHe do you real want help or are you just wasting time!
 

2fs2ns

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Re: What are these screws?

No, definetely want help, and I've been given alot already. This is my first large boat/outboard so I'm very uneducated! You guys have pointed out some pretty obvious stuff, but I had overlooked it.

Thanks again!
 
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