Wiring mess

[SimonStDavids]

As well as the glassing work on my hull I would also like to sort out the wiring and if possible fit a tachometer, the only problem is I haven't even got the slightest clue where to start

Here is a picture of the mess that is the console end, the choke doesn't work but ignition and kill switch do, there seems an awful of wires that don't go anywhere though So i am hoping they can be used for tach etc..

The engine end is at least tidyish looking and all of the wires appear to terminate somewhere (although i can't see exactly where!) with the exception of a thin red and thin black one.

Now back to the messy end, the pictures are really bad, so i am hoping there is standard otherwise i think i might be screwed

There is what there is:

Kill cord- Black wire connected,
White not connected

Choke- White with black stripe connected

Ignition- Brown connected
Black connected
White connected

The white wire also is joined to an orange wire that goes nowhere

Pink and Green wires go nowhere!

Any ideas where to start? I can take better photos of specific parts if needed and try and explain how each wire routes.

For info i have a 90's ish Yamaha built mariner with electric start but no ptt

[Pikey Dave]

I've seen worse...just! I'd start with a new switch panel & re-terminate the cable. Shouldn't be difficult & you will have relative peace of mind that you won't have problems when you least need them.

[yam man]

From memory green tacho , pink overheat / low oil goes to ground and White ignition stop / killswitch

[Festinghouse]

my advice, solder everything! much less likely to be affected by corrosion and vibration.

[9D280]

Originally Posted by Festinghouse

my advice, solder everything! much less likely to be affected by corrosion and vibration.

...but a total pain if you have to do a "halfway to wherever" bypass of a switch.

Simon,

First thing - google for "Yamaha outboard wiring colour scheme" - you'll get a few hits with the colour / function lists. How good is your electrical knowledge? If you can use a circuit tester it shouldn't take too long to figure out, and I'll tell you what you should be looking for round the ignition switch. if you are only comfortable with "plug & play" I won't bother confusing the issue.


In the meantime: (and be aware my wire colours are from memory, so don't take as gospel!)

There is what there is: My comments in italics

Kill cord- Black wire connected, (should be to earth)
White not connected (Should connect to the white on ifnition switch & both to a White on the loom from the engine)

Choke- White with black stripe connected (Hopefully to the choke solenoid via the loom - other contact to switched + from the ignition switch)

Ignition- Brown connected (hopefully to starter solenoid via the anti start in gear microswitch on your throttle/ gear lever(s))
Black connected (hopefully to earth via loom)

White connected to what? - presumably the ignition switch?
The white wire also is joined to an orange wire that goes nowhere I suspect that should join up in parallel with the deadman


Pink and Green wires go nowhere! One (green I think) is Tacho signal, other may be warning horn.


Assuming you have both Yam switch & engine loom, and they are of a similar age, just making sure the colours match is 90% of the job. If not have a crawl round the net - if the wiring colour charts don't help. There are a few wiring diagrams out there, the remotes end doesn't change much so even if the colours don't match you can follow them round the boat to figure it out.

Someone on here (Nos?) had a diagram for Yam 703 controls. The high level wiring & colours will be the same, but you may have extra connectors & fly leads for stuff like the anti start in gear switch which will be remote from the panel.

Hopefully this has not confused things further. If I get time tonight I'll look at Clymer & tell you what all the wires are supposed to connect to & what colour they should be.


Having said that - those switches look a bit corroded - you might be better just biting the bullet & buying a new set.

[SimonStDavids]

Thanks everyone, that is starting to be a bit clearer. i had tried loads of google searches using all sorts of terms, but hadn't thought about "yamaha outboard wiring scheme" Duh!

Wiring Color Codes for YAMAHA Outboard Motors.

I had thought about buying a new switch set but they seem pretty expensive so i thought it would be better to try and fix and improve what i have for now and the photos make the corrosion look worse than it is

My electrical knowledge could be described as skanty at best but I quite enjoy learning about how things work and giving things a go If it all goes horribly wrong then i guess i can take it and get a professional to look at it.

9D280 much appreciated i will try and trace where the wires outlined above terminate in the engine and try and describe a little bit more concisely the route the wires take.

RE- a tacho where would the green wire terminate in the engine just to check it does go somewhere and do i need a specific tacho? seen these of fleabay and seem quite cheap

Black Faced Rev Counter Tachometer Waterproof UV Proof | eBay

Would it work?

[9D280]

Not knowing the insides of your engine, the tacho signal wire will either find it's way to the ignition module or to the alternator side of the rectifier. If it goes to the rectifier (usually an independant box with 3 or 4 leads / terminals), based on your colour codes linked above I would expect it to share a terminal with a Green/white wire.

So, your diagram has confirmed some of the colours, so I can say with a little more certainty now:

White = stop. You should have a wire from the ignition module which will split at your console & go to both the deadman & the white wire on the ignition switch.

Brown = Start. To trace this start at the starter motor, follow the thick wire that doesn't go straight to the engine block. It should go to a relay (starter solenoid) On that relay will also be a "thin" brown wire to the console & a black to the engine block - the brown wire should go to a microswitch in your throttle / gear lever box, then on to the ignition switch's brown tail.

Red = +12V While you are at the starter solenoid in the engine, the thick cable form the battery is likely going to have a thin red also bolted to the same terminal heading off to the console. This is the +12 to feed the gauges / starter etc. It should go direct to the red wire on the ignition switch, and may have a connector near the switch to "T" 12V off for auxiliary stuff.

Blue = Choke. Somewhere near your carbs will be a solenoid. Usual story - one wire straight to the engine block, the other (blue) should go straight to the choke switch. From the other side of the choke switch there should be a connection to your switched +12 (yellow) out the back of the ignition switch - see below.

Yellow = Switched +12 v. This wire doesn't go anywhere near the engine, and should come out the back of your ignition switch. This essentially powers stuff you need when the engine is on, but stops it flattening the battery when ignition is off. This will likely have a multiple set of connectors hanging off it (probably 2 or 3). One should be connected to the choke as described above.

Pink = Warning horn. This should be connected to your alarm horn. It (just to complicate matters!) is a +ve signal when the trip switch(es) make contact (e.g low oil level, overheat) and so the pink wire on the engine could come from multiple sources, unless it goes to the "ignition" box along with the stop wire where the ignition module will deal with the spaghetti). If it doesnlt go straight to the ign module, places to check are - Oil tank level float, thermal switches usually live near the spark plugs on the cyl head. Pink wire to one side of the horn, other end to black (again, more of that below) If you don't have a Yammy horn, any electronics shop can sell you a 12V piezo buzzer. (make sure it's a loud one, as it will be buried in & muffled by your console!) In theory nothing to stop you using a 12V bulb on the panel either.

Black = Earth. This will again be connected at the engine, probably where the battery -ve wire is bolted to the engine block. This should have a multiple connector on the loom at the console end, these should go one to the ignition switch black, one to the horn and the rest are for earthing your tacho - dials - instrument lights etc.



As for the tacho you linked - maybe. Outboard tachos tend to count alternator pulses, so whether this one will have the requisite number of pulses / min when it appears to be counting sparks only an experiment will find out. Other thing (and I may be doing the maker a gross injustice here) is that "waterproof" for a car and "full IPx7" for a boat can be two very different degrees of waterproof. (as usually seen by the price )

I may have a Yam tacho going spare soon (Hopefully about to finally get a complete set of matching guages! :banana , but get your other electrics going first...

[SimonStDavids]

Right this is starting to make even more sense

Engine side is exactly as you described apart from when tracing the pink it goes nowhere!

The only thing i am not sure about is the green, it does go in to a black box (see photo) but can't quite get my head around the green yet!

Console end-

Pink goes nowhere but that figures now.

The white splits goes to ignition (black/red) and nowhere so i need to connect this to kill switch. Why does the switch work without this connected?

The blue goes nowhere, but i will reconnect to choke and hope it works.

Black splits and goes to kill switch and ignition (white/black)

Red becomes white/black and splits to choke and ignition.

I don't have yellow, but a black and yellow, do you think it is the same?

Let me know about the tacho,

[9D280]

Originally Posted by SimonStDavids

Right this is starting to make even more sense

Engine side is exactly as you described apart from when tracing the pink it goes nowhere!

The only thing i am not sure about is the green, it does go in to a black box (see photo) but can't quite get my head around the green yet!

That looks a loty like a rectifier to me.... try typing the part number on the side into a yam spares website & see what it thinks it is.

Originally Posted by SimonStDavids

Console end-

Pink goes nowhere but that figures now.

The white splits goes to ignition (black/red) and nowhere so i need to connect this to kill switch. Why does the switch work without this connected?

if only one wire is connected & it still works then I think your switch is properly gubbed - possibly shorting to "real" earth as opposed to "engine electrical earth" sufficient;ly to kill the ignition. If you have a multimeter, check there is no connection between one of the switch terminals & the panel or similar.

Originally Posted by SimonStDavids

The blue goes nowhere, but i will reconnect to choke and hope it works.

Black splits and goes to kill switch and ignition (white/black)

Red becomes white/black and splits to choke and ignition.

I don't have yellow, but a black and yellow, do you think it is the same?

Something don't smell right there..... Definetly a Yam switch module?

Originally Posted by SimonStDavids

Let me know about the tacho,

OK, will do.

[SimonStDavids]

Sorry for the delay, I have been glassing the deck back in and sea trialling it so electrics have been on one side.

But now back on with it!

I have the kill switch working again. The wire must have come loose when I pulled it all out as was working all season and only stopped when I started fiddling!

The choke still isn't. Reconnected the blue and nothing, checked the switch worked with multimeter so I guess either the wire or the solenoid is dead

Now I think the switch might hobbled together. It says mariner on the outside but the key is a Honda so I guess that the ignition barrel has been changed and might explain why it does't quite match up!

[9D280]

Easy way to check the loom is to swap to another known core & see if it works. (you may need a small jumper to connect the other core to the coil if it doesn't reach) & see if it fires.

Choke solenoid - can you move it by hand? That would at least tell you if it's mechanically jammed or not.

If wired correctly, normaly it will only fire if ignition is on. Check you have +12V feeding the switch first.

If not put your mutimeter to "ohms" & see what the resistance of the coil is. I'll try to remember to look it up in my Clymer when I get home & post what the reading should be. At a going in guess I'd be surprised if it's any more than about 50 Ohms, probably nearer 10-20. Needless to say open circuit is a dud coil.


Mixing engine makers' bits - There are now at least two of us on ribnet!

[SimonStDavids]

The plot thickens!

The solenoid seems to move freely so I don't think it is jammed and with the multimeter the ohms is somewhere between 0.4 and 0.5 on the lowest setting my cheap meter goes down to.

I will swap the blue for the redundant pink to check if the wire is dead but whilst checking a few things I noticed something very strange. I only appear to have about 6 volts at the console end of the loom???

I had this reading across the black and red in the loom and across the switched power from ignition to earth?? I was pretty sure it was supposed to be 12v

Engine starts fine and reads 12.6v across battery terminals. Any ideas what would cause this voltage drop and would it explain the choke not firing?

[9D280]

0.5 ohm is close enough - that's conducting. BUT 6V isn't going to move it! (or anything else designed to work at 12V - your tacho might not be gubbed after all)!

Does your starter work on the key? The starter itself is "hard wired" back to the battery, so gets the full 12V off the big chunky cables (via the solenoid). Your solenoid might be "light" enough to fire on 6V, or more likely the chances are your keyswitch or choke switch contacts are on their way out - you might be getting 12V out the "start" contact, but have a highly corroded "ignition on +12V" contact.

Best bet now is to chase the 6V back & find out where it turns to 12. You have already done the battery, so try the terminal where the small +12 to the remotes wire is connected in the engine (probably o nthe starter solenoid). Unplug the loom, check the pin there. then at the ignition switch. If you got 12V all the way, then try the two outputs of the switch +12 (ign) & Start. If you got +12 on both of them, try your choke switch. (which if it turns out to be gubbed is easily replacable with a big sprung toggle for about £3 from Maplin (remember to buy the waterproof cover for it!)

Corroded connector / switch contacts could give that sort of V drop. Most 12V electrical stuff will work to a greater or lesser extent down to about 10V, below that it's down to luck & the design of the widjet. Some electronics will wheeze on down to 8-ish V, but as the choke solenoid is a simple "turn electricity into mechanical movement" device if the V isn't there it isn't going to generate enough magnetic field to move anything.

Let us know where the V dissappears.

[SimonStDavids]

9D280 you are a blinking genius! Thank you for taking the time to help a fool!

Right here is what i have so far,

12v at the battery (actually nearly 13v) and the same at the starter solenoid.

12v at the console end between either the red and black or brown and black going into ignition, but not coming out on what i think is the switched power.

I guess that means there is something either busted or corroded in the switch? Are new ignition switches expensive?

Now to the choke, switched to the pink and boom choke worked Only problem now is that pulling the connectors on and of the choke switch have pulled off one of the terminals so i guess i will replace with a maplins one like suggested

[9D280]

At no load 13 & a bit V at the battery is a good thing!

I would guess if you managed to remove a terminal on the choke switch your ignition switch won't be too far behind.....

2 options:
1) a gallon of WD40 into the ign switch, turn it off & on a few dozen times & hope.
2) new switch.

no idea of the cost, it's one of the few things on my rig that haven't died on me so far!

If you are Ok with solderng or crimping, and have the switches on a panel rather than rammed into the remote control, there is an argument that most 2- stroke generation ignition switches would work as long as it had "short on off", switched power & a sprung start position. Most of the modern ones have a "push key in to choke" function, so removing the separate choke switch.

If you want to be a bit creative, what is likely a lower budget option is a simple Maplin key switch (on- off to break ignition - do you even need it with your use?), a DPDT with one side wired "power" the other (opposing) side wired across the deadman (the stop-go selector) and a couple of push buttons / sprung toggles for start & choke. The only dowwn side (as I found on my electrical rebuild) is that the only switches they do vaguely IP rated are the toggles with the rubber covers. Having said that, I bet someone like RS would stock them. (other electrical retailers are avaialble!)