225 Johnson Ocean Runner won't shut down

[art1109]

Last year I replaced the power pack on this engine. Right after that I started to have trouble shutting it off. At first I chased what I thought was a bad ground ire going to the keyswitch. But the problem is still there.
What happen is that when you turn the key off it shuts down three cylinders as if I'm shifting. I have read out the wiring going to the keyswitch, and it checks out fine according to the manual.
I think the key here is that it kills the three cylinders. I have even taken the b/y wire at the switch and used a jumper wire to ground it out. All it did was kill the three cylinders.
I am wondering if it was possible for me to cross something at the power pack to cause this. Looking at the manual I see the b/y and the b/o and the diode. Could my problem be in this area? Please help, I need a little insight to how this functions.
Art

 

[ezeke]

Re: 225 Johnson Ocean Runner won't shut down

There is only one black and yellow kill wire in the harness leading from the control to the engine;

edit:

All six cylinders should be shut down instantly when the power pack is grounded by the ignition switch.

The 1992 powerpack had two black/yellow wires in two amphenol plugs, the 1993 powerpack is only supposed to have one.

 

[art1109]

Re: 225 Johnson Ocean Runner won't shut down

Yes, there is one amphenol connector at the powerpack with the b/y wire. It also has the b/o wire in it.
I agree that all six cylinders should shut down if this is grounded. But that is not what is happening.
How do the three shut down when shifting? Somehow the signal going to three cylinders is shut down. If this is what is happening to me instead of killing all six, it could be in the wiring. Let me know what you think.
Art

 

[tashasdaddy]

Re: 225 Johnson Ocean Runner won't shut down

dirty connection.

 

[Greg_E]

Re: 225 Johnson Ocean Runner won't shut down

I don't know if your newer engine is the same, but on my 1988, the shift interrupt switch has a diode in the attached wiring harness. Run your fingers down the sleeve material that covers the wires, and you will find the diode, midway in the harness. If the diode is open, that side of the power pack is not shorted to ground, when the key switch is turned off. The engine will continue to run on 3 cylinders.
You can check the diode with a multimeter set to ohms. Connect the meter leads to the two wires going to the switch. Actuate the switch. The meter should read either infinite ohms or very low ohms. Now reverse the meter leads. the reading should be the opposite of what you first measured. The diode allows current to flow in one direction but blocks it in the other direction. When you turn off the ignition switch, that side of the powerpack is shorted to ground through the diode. If there is a bad connection, open diode, or break in the harness, it continues to run on 3 cylinders.
The shift interrupt switch is over $100. You can find a blocking diode at Radio Shack or any electronics supply house for a couple dollars. It will have a number like 1N5004 printed on the diode (that is just an example, not necessarily the correct part number.) If you can't find the exact number, you can use something with similar specs. Also, when you install the diode, make sure you put it in the harness the way the old one came out. There is a silver band(- cathode) on one end of the diode. Make note of which end the old one is installed, and put the new one in the same way.

I don't know if the switch on your newer engine is in the same place, but mine is tucked in near the base of the powerhead where the shift and throttle linkage is. Just follow the wires from the powerpack and you will find
it.

You mentioned that this started after replacing the powerpack. Another thing to check for is a broken pin on the plug for the black/yel wire to the shift interrupt sw. The wire will separate from the crimp connector, but the rubber boot holds the wire in place, so it looks like it's a good connection.

 

[Greg_E]

Re: 225 Johnson Ocean Runner won't shut down

I had a chance to look at the schematic for a 1994 V6. The diode appears to be located in the main harness before it plugs into the shift interrupt switch harness, unlike my 1988 which has the diode in the switch harness.
There is a two pin plug on the starboard side of the powerpack. The "B" connector(Blk/Yel wire) is for the port side and goes directly back to the ignition switch. When you turn the key off, that half of the power pack is shorted to ground, and those three cylinders wont fire.
The "A" connector (Blk/Orn wire) goes to the anode (+) of the blocking diode. The cathode(-) of the diode is spliced into the Blk/Yel wire for the port side, somewhere in the main harness.
When things are working properly, The "B" side (port) is shorted to ground directly through the ignition switch. The "A" side(stbd) should also be shorted to ground, but the circuit goes through the diode.
You either have a broken pin or socket (Blk/Orn wire) in the two pin connector that goes into the powerpack or the diode is open.
Also on the anode (+) side of the diode is a BLK/Yel wire that goes to the shift interrupt switch. The black wire from the shift interrupt switch goes to the ground stud on the powerpack. When you shift, the switch momentarily shorts the "A" side to ground, killing the starboard power pack for a split second, to decrease wear on the gearcase components. The port side is not shorted to ground, because the diode blocks current flow in that direction.
If you pop the switch out of its holder and depress the switch with the engine running, The starboard cylinders should cut out. If that doesn't happen the culprit is probably the "A" pin or socket in the two pin plug. If you turn off the engine and it is running on three cylinders, depress the shift switch. If the engine stops, the diode is open and the 2 pin connector is OK. The key switch killed the port side (but not the stbd side like it should have), and the shift interrupt switch killed the starboard side , stopping the engine.
If the problem is intermittent, one of the wires is probably hanging by a single strand or barely touching the broken connector.
That's all clear as mud right?

 

[art1109]

Re: 225 Johnson Ocean Runner won't shut down

Men,
I want to say thank-you to all who have responded to my post. Greg, I know that it takes time to respond to an inquiry with the amount of detail at which you did. I appreciate the time you have put in to helping me. Here's the rub, since my post I haven't made it back to do any further troubleshooting until today. Too many other responsibilities have put my boat on the back burner. But I know that after putting time into helping someone, we would at least like know the results.
Today I found a bad shift switch. It is reading open whether I press it or not. My plan is to buy one and try to get it installed this week.
I have read out the wiring between the plug at the engine and the keyswitch and safety lanyard. I believe I thorougly understand the circuit and that I have it correct. I haven't checked out the harness on the engine yet. But now that I have read these replies I have a better feel for how both sides of the powerpack get grounded out. I can check for bad connections and/or broken wires.
I will post my findings when I can. Again, thanks to all
Art

 

[Greg_E]

Re: 225 Johnson Ocean Runner won't shut down

Art,
If the diode in the haress isn't open, there is very little that can go wrong with the switch itself.
You can buy a diode at Radio Shack for a couple bucks.
It's possible that if the switch harness has been flexed repeatedy, the lead on the diode broke.
If the diode is not bad, try this.
If the boat has been sitting for a long time, the copper contacts inside the switch may have tarnished, causing a bad connection. Try manually actuating the switch repeatedly (until you get tired of doing it) to try to clean the contacts. The actuator on the switch is o ringed, so I doubt water got in it. If neither thing works, buy the new switch for about $110.

 

[dhoover75]

Re: 225 Johnson Ocean Runner won't shut down

Greg E, I want to thank you for making this post so long ago because it helped me figure out my problem yesterday. However I cannot find a replacement diode anywhere. The only numbers on this diode is DII J10 . nobody seems to be able to crossreference that number. Do you know what size diode this is or amperage or something so that I can find one. It is from a 92 225 HP Johnson.

Thanks

 

[seahorse5]

Re: 225 Johnson Ocean Runner won't shut down

You can get a diode from your Evinrude dealer, part no. 583898

 

[Greg_E]

Re: 225 Johnson Ocean Runner won't shut down

I couldn't find the exact diode at radio shack, so I used a 1N5402. It worked fine.
The best course of action would be to use the correct one fron Evinrude.

 

[ezeke]

Re: 225 Johnson Ocean Runner won't shut down

What is the part number on your powerpack?