ignition switches keep failing attn Joe Reeves

[25whaler]

I have twin 150s (1986) and have replaced ignition switches twice in about 1.5 years. Each time it is the kill circuit part of it that wont allow the engine to start (black and yellow wire)<br />This last time I could not get the one started so I took to the local mechanic because I thought it was a fuel problem (did not even think it could be the switch again) He changed ignition switch and eventhing is great now. He also said that the kill wire (BLK/YLW) had power to it. This is not supposed to have power only ground when stopping?? The problem I beleive is from the harnes back to switch. PLease let me know if anyone has any idea what could be causing this. I cannot see where the two motor would be linked inorder to be doing this?? I do have a two battery set up with one selector switch. (could it be here??) Thanks

 

[Joe Reeves]

Re: ignition switches keep failing attn Joe Reeves

That problem is caused by having the ignition switch fail in a manner whereas a very slight bit of voltage is allowed to short out within the ignition switch from the "B" (battery) or "A" (accessory) terminal to the raised boss type "M" (magneto) terminal.<br /><br />Why the switches would fail repeatedly could be a matter of where they're located. If they're in a vertical position/location, or close to a vertical position/location on top of a console where water has access to the keyhole, that might be the cause.<br /><br />Strange though as I've seen hundreds of switches installed in that manner whereas no problem of that nature has occurred. Makes one wonder about the quality of the ignition switch.

 

[25whaler]

Re: ignition switches keep failing attn Joe Reeves

Joe,<br />Thanks for the respone. Both keys are located in a veritical position. They do not get water very much at all. TOp is always up and they are kinda out of the way. As for switches I am using OMC replacements. Question for you is can I do anything to these switches (ie rubber coat them etc) also I do keep the key in should I be taking it out???

 

[Joe Reeves]

Re: ignition switches keep failing attn Joe Reeves

You could coat the terminals with a liquid insulating solution but the problem is internal.<br /><br />Your reply above has me thinking that the switches shouldn't be going bad, however I always remove the keys for security reasons.<br /><br />Here's a thought.... Should any of your accessories have their black ground wire leading to those black/yellow wires (directly or indirectly), mistakenly using the black/yellow wire as a ground, that would allow the 12 volts that is being applied to the accessory to flow to that accessory, then out of that accessory at a lesser voltage to the black/yellow wire terminal of the ignition switch.

 

[25whaler]

Re: ignition switches keep failing attn Joe Reeves

Joe, Thanks for the help. I will try tracing the black and yellows wire to see if they share ground or are connected to any accesories?? I appreciate your help. Now that I think of it what your saying makes alot of sense as I was confused why I was going thru so many switches. Question I have is why will changing the switch fix the problem. If the old switch is getting a small amount of power thru it why wouldnt the new one?? or does it build up over time (is that possible??) Joe thanks again for your advice its great that you are willing to share your knowledge. Greatly appreciated I am sure not only by myself.