Wiring

[tich]

Hi!<br />I have been reading,with some interest,the post from Oceanmist. In your replies a lot was mentioned about the cut-off switch,the safety switch and the two wires that come from the points. The wiring diagram in the manual that I have shows that there are three wires together on each set of points. One of these is from the condensor,one is from the coil and one from each set of points goes through the plate, one of which goes to the centre of the cut-out switch along with a wire which comes from the starter switch,the wire from the other set of points goes directly to the starter switch. When the engine came into my possesion all the wires had been disconnected and were just hanging in mid-air so I had to re-wire everything. I did so as per the diagram but on turning the key the coils got very hot and I had to turn everything off rather rapidly. Does all that sound clear or am I talking out of my rear end?..<br />Anyway, my point is how accurate are these wiring diagrams. Have I got it completely wrong somewhere. If so maybe you can help me out.<br />I was tempted to put the diagram from the manual on here for you to look at but Im sure someone would tell me that I was breaking somekind of copyright law.<br />Any help would be very welcome. A diagram of some sort would be wonderful.<br />Regards<br />Tich

 

[CATransplant]

Re: Wiring

Wrong connection on the switch. The two black wires from under the flywheel should NEVER have 12 volts go through them. Their only function is to kill the engine, which is done by shorting both wires together.<br /><br />One wire is supposed to go to the plug on the side of the engine and from there to the external harness and to one of the M terminals on the ignition switch.<br /><br />The other one goes to the vacuum safety switch. Another wire also connects to the same terminal on the safety switch and goes, like the other one, to the plug on the engine, and to the other M terminal on the ignition switch.<br /><br />When the switch is turned off the two M terminals are connected, shorting out these two wires and grounding both coils so they can't fire. If 12 V goes to the coils, it's very likely to burn them out.<br /><br />During initial testing, you can leave these two wires disconnected altogether, since any short in them will keep the spark from happening.<br /><br />Now that you have had 12V connected to those wires, you may well have burned out the coils. Time will tell. If you still have spark, you didn't do any damage. If no spark, you may have burned out the coils and will have to replace them. The diagram is accurate. You just got the wires connected to the wrong terminals on the switch.

 

[lark2004]

Re: Wiring

hey tich, whats your Email address? I might be able to help you out.

 

[tich]

Re: Wiring

As always,thank you CAT for your help. I am truely grateful.<br /><br />For lark2004 my e-mail address is bullterrier69@hotmail.com<br />Any diagratic help would be wonderful.<br /><br />Thanks again.

 

[tich]

Re: Wiring

If I may (at the risk of becoming a pest)pick your brains again Sir CAT. On the back of the ignition switch there are 7 connections(terminals). 1 single connection and 3 double connections. The single connection is marked S. The double connection on the right of the S is marked AUX. The double connection on the left of the S is marked IGN. And finally the double connection opposite the S is marked BAT. You mentioned an M connection(terminal) in your previous reply. There isnt an M terminal on the back of the switch so I can only assume the switch that I have is different to the one that you are explaining. That being the case, maybe you can help me to sort out the delemma that I seem to have i.e what goes where. Pushing my luck even more, you also mentioned a plug on the side of the engine where the 2 black wires from under the flywheel eventually meet up. Could you give me a little more info as to where this plug is?<br /><br />

 

[CATransplant]

Re: Wiring

That's not a normal switch for an OMC outboard, which should have 5 terminals. I am afraid I can't help you with the functions of that switch, although some of it makes sense.<br /><br />The BAT connector is for the Positive 12 connection to the battery. The S connection is the connection for the solenoid wire. Aux provides 12V for auxiliary features like gauges, radios, etc. The IGN terminals are probably the magneto terminals. What you need to do is measure the continuity between the two. There should be Zero continuity when the key is in the on position, and Full continuity when the key is in the off position. Remember...you want to short out those two black wires to each other when you turn the key off.<br /><br />Since your keyswitch doesn't have the usual OMC markings, you'll have to experiment. But...under NO circumstances is 12V to be applied to the black wires.<br /><br />I can't remember, offhand, which year's motor you have. It should have a connector on the starboard side of the engine, in the lower cowling. That would accept a plug from the harness that goes to the controls. In many cases, these plugs have been removed, which may be the situation in your case.

 

[tich]

Re: Wiring

Thank you Sir!

 

[CATransplant]

Re: Wiring

Not a problem at all. Another solution for the kill circuit is to simply use a Normally Open pushbutton switch. That's what I did, installed in the console next to the keyswitch. My keyswitch didn't make any sense to me, so I simply took the two wires used for killing the engine and connected them to that pushbutton switch. To kill the engine, I just push the button.<br /><br />There is always a solution for any problem.

 

[Paul Moir]

Re: Wiring

By the way folks, feel free to copy/share/modify my 28hp schematic (which is basically the same as any Big Twin schematic):<br /> http://files.filehosting.org/pr12156.pdf <br />The original is in Corel .CDR format, but if anyone wants to modify it for another outboard just email me at paul.moir@ns.sympatico.ca for the original.<br /><br />On another note, to save a wire in the harness on my 28hp, I used a pair of diodes and ground for a kill switch. Like this:<br />

Mag line ----|<----0<br />Ground -- Switch --|<br />Mag line ----|<----0

(if you can see a schematic in there somewhere. The diodes are 'backwards' because the ignition pulses from the magneto are negative. I used 600v 1 amp diodes if my memory serves me.

 

[CATransplant]

Re: Wiring

Thanks Paul! That will be helpful to many Big Twin owners here.

 

[Paul Moir]

Re: Wiring

No problem. Heck, even send me a list of changes and I'll make the PDF myself. A bunch of the OEM service manuals don't come with a schematic, and the ones in the Seloc manual are in black & white, , so it would be a good idea to have some free ones floating around.

 

[tich]

Re: Wiring

I originaly had the two wires connected to a push button switch as you suggested CAT but I wanted to see if I could wire it up to the ignition switch as per the diagram in the manual that I have. It now appears that that diagram is not correct for my situation so it will be interesting to see how Pauls diagram compares.<br />Thank you Sir Paul for that!<br /><br />Thankyou all very much

 

[CATransplant]

Re: Wiring

Keep the faith, tich. You'll get it all sorted.