voltage on yellow-black ignition wire

[Timeking]

I have gone thru the tests, and my 2000 OIS power pack on my 2001 Johnson 150hp is the cause for no spark on starboard bank. I am ordering new one. OK, so something made the power pack croak, and I don't want to install new pack only to have it croak as well. CDI installation pdf says to check for voltage on the yellow-black wire that runs back up to the ignition switch (or at least there is a yellow-black wire on the switch). If voltage is greater than 2 volts, per CDI, it will blow up the new power pack. I tested this and there is variable voltage on this wire to ground of 0.3 to 1.1 VDC with ignition ON but engine NOT running (it will run on 3 cylinders).

Why is there ANY voltage on this wire?!?

Shouldn't it be ZERO volts to ground? Does this indicate leakage thru the ignition switch somehow, and even though the voltage is less than 2 volts, a harbinger of the ignition switch shorting out, blowing up my new power pack?

 

[Bosunsmate]

Re: voltage on yellow-black ignition wire

Perfectly there shouldnt be, but i suppose due to the high voltage in those packs a bit of induced current is to be expected

 

[boobie]

Re: voltage on yellow-black ignition wire

I would have to guess the ign switch. If you have an old Evinrude dlr in your area (which I think you do ) and he has a condenser tester you can check the ignition switch for any leakage between the terminals on it. The procedure is in the service manual and I have done it.

 

[Timeking]

Re: voltage on yellow-black ignition wire

I am confused by reference to "condenser tester". Do you mean ohm-meter? My manual says merely to check for continuity/resistance and lack thereof at different terminals when in off-run-start-choke modes. Is that the "procedure in the service manual" that you are referring to? Or is there a different test?

 

[Timeking]

Re: voltage on yellow-black ignition wire

I actually have (it turns out) a capacitance meter, and "capacitors" and "condensers" are used interchangeably. So, if that is what you think I need, I have it. But I don't know what readings should be where/when. ???

 

[Chris1956]

Re: voltage on yellow-black ignition wire

You need to find out where the voltage is coming from and how it gets onto the black/yellow. Disconnect the black/yellow from the powerpack and test for voltage. Now disconnect the ground from the ign switch and test for voltage. Next disconnect the red from the ign switch and test for voltage. There is a red wire from the starter solenoid to the powerpack. This provides voltage to PP when motor is cranking. Disconnect that wire and check for voltage. If you can narrow it down to the ign switch, replace it. If it comes from the red wire, maybe the pack itself is doing it.

 

[Joe Reeves]

Re: voltage on yellow-black ignition wire

Voltage To Powerpack Failures
(Magneto Capacitance Discharge Systems)
(J. Reeves)

The usual cause of having those type powerpacks fail repeatedly is having a very small of voltage applied to the Black/Yellow wire (Kill Circuit) at the pack. Test as follows.

Disconnect the Black/Yellow wire at the powerpack.

Insert either a ampere meter or a volt meter set to its lowest DC voltage reading between that Black Yellow wire and ground.

With the ignition key in the OFF position, observe the meter reading. Now turn the ignition key to the ON position and again observe the meter reading.

Any reading, movement of the meter needle, even a microvolt, would indicate that battery voltage is being applied to that Black/Yellow wire. If a reading is present, remove the other end of that Black/Yellow from the raised terminal of the ignition switch.

If the reading ceases to exist when the Black/Yellow wire is removed from the ignition switch, replace the switch. If the reading continues to exist, there would be a short of some kind in either the engine or instrument wiring harness.... to determine which, simply unplug the large RED electrical plug at the engine which would eliminate the instrument cable.

Note that the black/yellow wire must not have any other wire attached to it for the following reason!

Keep in mind that any accessory that has 12 volts running to it, especially when turned on, will have voltage flowing thru it and trailering out thru its black ground wire to complete the circuit. If that accessory has it's black ground wire attached to the "M" terminal that the black/yellow wire is attached to.... you will have voltage flowing directly to the powerpack.

 

[Timeking]

Re: voltage on yellow-black ignition wire

Unlike my previous engine, there is no big RED plug. Further, this thing has the MWS (modular wiring system), so there is no red nor black wire going to the ignition switch. I unplugged the switch, and check for continuity between all 5 of the pins and the pin that connects to the black-yellow, and resistance was infinite (open). So I am assuming this is telling me that the switch itself is OK. To remove the black-yellow at the switch end will mean actually cutting that wire. I am hesitant to do that. At this point, I am playing and losing 'stump the chump'.

 

[Joe Reeves]

Re: voltage on yellow-black ignition wire

Unlike my previous engine, there is no big RED plug. Further, this thing has the MWS (modular wiring system), so there is no red nor black wire going to the ignition switch.

Sorry, it had slipped my mind that the large RED electrical plug was eliminated later in years (I retired in 1991). However, doesn't that black/yellow wire somehow disconnect from the ignition switch... plug in, whatever?

In your very first post, you ask why there is voltage on that wire (black/yellow). If voltage is present on that black/yellow wire with the engine NOT RUNNING but the key is in the RUN position, the only cause would be either a faulty shorted ignition switch OR a ground wire from some accessory is somehow routed to one of those "M" terminals of the ignition switch.

Am I correct in assuming that your engine still uses a ignition switch with six (6) terminals marked: B, A, C, M, M, S. ?

 

[Timeking]

Re: voltage on yellow-black ignition wire

Yes, the ignition switch has 6 terminals, but all those wires are sealed on and go down their own wires down the MWS cabling. I am measuring voltage between ground and the black-yellow kill wire on the unplugged connector that goes into the power pack. The red-yellow wire that goes to the starter solenoid is also on this connector, and since I am taking measurements on the unplugged connector, the red-yellow wire is also unplugged. So the phantom (?) voltage is not coming from the wire to the starter solenoid. I used alligator clips and an insertion pin to get solid connections to my voltmeter. Being destructive at this point, I took a pair of cutters and cut the black-yellow at the ignition switch.

0.38 volts with switch on and BY connected at switch
0.26 volts with switch on and BY disconnected at switch
0.16 volts with switch off and BY disconnected
0 volts with switch off and BY connected (cuz it is grounded when connected)

Disconnecting the various dashboard instrumentation plugs had no effect on these readings.

I am thinking that having a little bit of voltage on this wire is 'normal'. That is potentially why the CDI installation instructions say "less than 2 volts on the kill switch wire", not zero volts no way no how? The 0.16 volts on the kill wire with the the switch OFF and the black-yellow wire when disconnected at the ignition switch with the switch off scares me, but maybe that is OK. ????

Maybe 22 feet of wire layed out linearly will generate a small voltage all on its own from cell phone towers, radio and TV transmission, and alien invasion motherships???? I know my Dad told me how WVa hillbillies used to tear down telegraph lines for the wire, and wrap that around their houses enough times to run a lightbulb for free off the atmospheric electromagnetic charge, and how KDKA radio station used to transmit with so many watts in the 1930's that people would actually pick up radio on the fillings in their teeth.

All I want to know at this point is two things:

1. Should I install the $200 power pack and get on my hands and knees and pray it doesn't blow up?

2. Should I continue sitting in my boat parked in the yard drinking massive amounts of beer and just pretend I'm out fishing?

If number 2 please be advised that my wife is getting awfully bitchy when I have her pull line off the reel now and then so I can stand drunkenly up in the boat yelling "Fish On!!!!". There is 'fighting' and there is 'fightin'. At this point, I'm digging both.

 

[boobie]

Re: voltage on yellow-black ignition wire

I go with option # 2. LOL

 

[Joe Reeves]

Re: voltage on yellow-black ignition wire

Yes, the ignition switch has 6 terminals, but all those wires are sealed on and go down their own wires down the MWS cabling.

Okay then... You've just described an ignition switch that is shorted out resulting in voltage being thrown to the "M" terminal that the black/yellow wire is attached to.

From how you have described the wiring harness setup (which I'm not familiar with), I am somewhat puzzled. Just for the the sake of argument, say the ignition switch somehow got the threaded portion cracked and broke off..... it seems very unlikely to me that one would need to cut every wire leading to it in order to change it out to a new one. How would one go about installing a new ignition switch?

Boobie??

 

[Timeking]

Re: voltage on yellow-black ignition wire

No, the ignition wiring is a "module" that unplugs under the dash. Here is a picture of it (I could not find this part elsewhere)

Johnson Evinrude Ignition Safety Cut Off Switch 176408 | eBay

As you can see, I had to cut the black-yellow on the harness, as otherwise you had to unplug the whole switch.

As reported above, the pin at the switch end that is connected to the black-yellow has infinite resistance to all the other 5 pins when the ignition switch is in the ON position. When in the OFF position, that pin gets shorted to ground, as it should, as it stops the engine. So I don't see how the switch is at fault.

And I don't see how it is possible to have voltage on a wire that is disconnected at both ends!!!!!! I sat down and highlighted the path of that wire on my wiring diagram, and it just goes from the plug on the power pack to the plug on the end of the modular ignition switch harness.

 

[Timeking]

Re: voltage on yellow-black ignition wire

That modular switch is part number 0176408.

 

[Joe Reeves]

Re: voltage on yellow-black ignition wire

No, the ignition wiring is a "module" that unplugs under the dash. Here is a picture of it.

Amazing, and I do appreciate the time and trouble it took for you to get those pictures together. Now, I understand.

Bottom line is that instead of making something easier, the engineers in their divine wisdom have once again forced upon us another increasing flow of sophistication, and as someone once said to me back in the late 1950's.... "Sophistication Breeds Problems", a quote I have obviously never forgotten.

And since this is a design of which I have no knowledge, I shall back out of here advice wise and simply lurk in the background to view the eventual solution.

 

[Timeking]

Re: voltage on yellow-black ignition wire

Bummer Joe, but thanks for the effort!

So ... being a scientist ... I did an experiment. I stretched a 30 foot 2 conductor speaker wire out on my driveway, which was connected to absolutely nothing. The DC voltage when measured at one end of the wire, one conductor to the other, was ... ta da ... 0.174 Volts!! So I am thinking that the voltage I am seeing on the kill switch wire is just phantom DC, and I should just go ahead and swap out the power pack. This also explains why CDI says "less than 2 volts" on the kill switch wire, not "zero volts".

I am also thinking that if I had an analog voltmeter (I actually have a Simpson meter but it is broken) that it would show zero volts because the meter workings would provide sufficient load to drain off the phantom DC voltage I am picking up with my stupid high-tech auto-ranging digital meter which I am thinking provides next to zero load on the measured line. "Sophistication breeds problems." I think you have something there......

 

[Chris1956]

Re: voltage on yellow-black ignition wire

I think your voltmeter is inaccurate. Of course it could be an operator head space issue as well.

 

[Timeking]

Re: voltage on yellow-black ignition wire

check out What is Phantom Voltage—induced voltage?

With absolutely no corresponding amperage there can be voltage.

 

[hweeres]

Hi timeline,

i have the very same predicament and see 0.08 to 0.33 V on that wire, it actually goes up when I run the bilge.

But I cannot find any bad wires or switch issues

did you ever resolve it or just installed the new pack and got it working without frying the new ignition module?

thanks !

 

[GA_Boater]

Timeking has been gone for 4 years.

Closed.