Wire Harness Fuzzies

[WetRaider]

Wiring up the boat while I wait for resin to set up ...
I've got a 7-pin Mercury boat side harness coming from the motor into the splash well.
I've got a new Mercury ignition switch, "push-to-choke" style.

PO's wiring job consisted of wires changing colors, cut & capped wires, wires running from under the dash to under the splash well - spliced - then back under the dash again, about 70 zip ties and a roll and a half of cheap electrical tape.

The graphic below shows the wires coming from my ignition switch - the wiring diagram packaged with the switch shows all but the white wire going to a "14-pin ignition key/choke/horn harness"  ... I don't have one of those.
It shoes the white lead being "outbound" to the "analog instrument harness."  ... I don't have one of those either.

Can someone give me a color-to-color idea of how this needs to be hooked up?  Why would the ignition split the purple wires?

[Rich_V174SS]

Wire: Key Switch - to - Harness

red to red
black to black
purple to white & your gauges
yellow/red thru the neutral safety to yellow

I would guess the purple is split because it needs to send power to the engine and the gauges simultaneously. I'm not sure what purpose the white wire serves unless it is supposed to power the gauges, a check with a test light will tell if there's power on the wire with the key on and off. I'm not sure if the yellow/black is meant for the magneto or the choke, again a test with a light will determine its usage. If the test light goes on when the key is on and pushed to choke then it's for the choke and you would connect it to the gray wire. If nothing happens and a continuity meter shows it tied to ground when the key is off then it's for the magneto and is connected to the salmon colored wire of the harness. Of the purple wires, does one of them have a white trace or are they both solid purple?

[WetRaider]

They are both solid purple.

This is the diagram supplied with the ignition switch.

[WetRaider]

It looks like maybe the white from the boat side harness should go to the white lead ... at least if I'm looking at their diagram properly.  I know you shouldn't make assumptions, but if the white were "outbound" as I originally thought, then it would show the lead pulling from the bundle coming from the instrument harness, rather than from the harness that connects to the "14-pin harness."

I know my brown from the boat side harness is the tach sender, so it wouldn't pass through the ignition switch at all.  

red-to-red
black-to-black
yellow-to-yellow/red
white-to-white?
brown-to-tach
salmon-to- ??
gray-to-  ??

I've got two purples and a black/yellow left at the ignition ... and the two purples are both solid.

My hull/deck is still split, so I don't have the motor hung.  It's been real handy to have my deck at standing height to mess with wiring.  I can get it all loomed and tucked away before I drop the deck back down.  That said - I can't hook it up to anything to test the wires ... unless it would work just dragging the battery out to connect my main power leads.  I'd also have to bypass the neutral safety.

[Rich_V174SS]

And they didn't provide a pinout label for the key switch? I suspect the white wire doesn't go to the analog instrument harness, they just decided to send it through another connector to the engine because I guess they ran out of pinouts in the main connector. So I think the white or the yellow/black are for the choke and magneto but the best way to tell is with a test light or an ohm meter.

The old color codes in your engine harness are:

red - battery
black - ground
yellow - start
salmon - magneto
brown - tach
gray - choke
white - ignition

[WetRaider]

If I had the battery connected, and the key pushed in, a test light would tell me if I've got a closed circuit between ground & choke wire, correct?

[Rich_V174SS]

Yes, the key would have to be in the on position though. With the test light you can also determine which wires like the purple and white wires will have power when the key is on.

[WetRaider]

Wire harness to ignition is in - minus the two wires needed to test.  Everything is bundled and tied nicely.  Looks crisp.  And about 120 total feet less wire in the boat!

Trim switch question now ... this switch was on the boat when I bought it.  The trailer button worked for the first couple days, after that the trim switch would lift that motor all the way up.  

I've got 6 wires on the back ... two on the trailer switch (red & blue with white stripe), and 4 on the trim switch (solid reed, green with white stripe, red with purple stripe, and purple with white stripe) .... I tried to trace back the wires through the spaghetti bowl and haven't found the ends (I think they splice and change color somewhere under a baseball of electrical tape).

Can I get some help with how to hook this up?  I'll be ready to drop the deck and tab in the floor once I get this wired up and tucked out of the way.

[dorelse]

I've never seen an outboard with a Trailer button.

[WetRaider]

I'm happy to bypass the trailer button altogether, but that still leaves 4 wires that I can't match up anywhere.
I've got blue and green run to the trim pump, power & ground to the pump from the battery -

[WetRaider]

I've just about got it figured out ...
the trim switch has 6 terminals on the back ... two vertical rows of three ... the two middle terminals have a red wire (both solid red) ... where do these go?  Ignition maybe?  Surely not, because you want to be able to activate the trim without needing the key ... straight power?

[dorelse]

I can only comment on my I/O setup Dan...so...I don't think that's much help to you.

[Rich_V174SS]

Yes, the early Merc outboards came with a trim limit, my '83 Merc 115 has a limit switch but I'm not utilizing it, it's bypassed. You only need three wires to operate the trim without the limit - red from the trim pump to supply power to the switch, and the blue & green from the trim switch. The blue and green wires go to the trim solenoids on the trim pump, the blue to the up solenoid and the green to the down solenoid. Those wires trigger the respective solenoid for the direction you want the drive to go.

[Jerry]

Because of the dual helm steering I cant use the tilt, and the trim limit is a must.

[WetRaider]

Look what I found under the baseball of electrical tape!

Not sure that it helps me much ... For the sake of this conversation, I'll call it the blind harness. I'll toss out the blind harness, because it has no plug at the other end, all hard-wired.  No sense in having an extra connection if I don't need it and my wires are long enough.

This is what I'm looking at - from the boat side motor harness, to the blind harness, to the ignition switch

Red, to red, to red
Yellow, to yellow/red, to yellow/red
Black, to purple/white, to black
Gray, to yellow/black, to ??
Brown, to gray, to Tachometer
White, to purple, to purple ?
Salmon, to black/yellow, to black/yellow?

Maybe I can get there with this ... if the white to purple and black/yellow are correct, then that leaves me only trying to figure out the choke - which is gray, to yellow/black, to either white or purple. 

[WetRaider]

I should be good to go ...
here's how it worked out.

Red from the boat harness to red on the ignition
Black from the boat harness to black on the ignition
Salmon on the boat harness to black/yellow on the ignition
Yellow on the boat harness to yellow/red on the ignition
Gray on the boat harness to white on the ignition
White on the boat harness is capped - not used
Brown on the boat harness is to Tachometer

Purple on the ignition switch is outbound accessory.  I can use either my white from the boat harness to power the gauges, or the purple from the ignition.

When I hang the motor, I'll update if it works.  Otherwise I'm going to need McGyver to show up at our Rathbun weekend.