1990 Johnson 200 Won't Shut Off

rapishorrid

Seaman Apprentice
Joined
Apr 2, 2016
Messages
30
My 1990 Johnson 200hp (J200TXESM) won't shut off when the key is turned to off, the kill switch is pulled or the battery switched is turned to off. Only way I've been able to stop it is by pulling the boots off the spark plugs. Connections at the ignition and the motor appear to be good for the yellow/black striped wire. Any ideas on where to start with this?
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Disconnect the black/yellow wire from the power pack and ground out the pack. If it shuts off you've got boat wiring probs. If not, you've got pack probs.
 

rapishorrid

Seaman Apprentice
Joined
Apr 2, 2016
Messages
30
Disconnect the black/yellow wire from the power pack and ground out the pack. If it shuts off you've got boat wiring probs. If not, you've got pack probs.

Which wire do I connect the ground to in the pack? Am I disconnecting the b/y wire from the pack and then putting a ground to where it was connected?
 
Last edited:

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Yes, You're grounding out the pack where the B/Y wire WAS connected.
 
Last edited:

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
If I'm thinking correctly, your 200HP should be a V6 with two power packs. Seems unlikely that both power packs would be bad. Regardless, the test would still be valid. If you do get into the wiring, The black/yellow wire has to make contact with the black wire to kill the ignition. One of those two wouldn't be getting through to the control box. I'd check the main harness connector first.
 

rapishorrid

Seaman Apprentice
Joined
Apr 2, 2016
Messages
30
Boobie is correct, the motor only has one power pack.

Here is my understanding of how the kill circuit works: power is sent from the powerpack down the b/y wire to the ignition & kill switch. When the ignition is on and the killswitch lanyard attached this is a closed circuit that returns power back to the pack (presumably via the ignition wire that provided power to the pack in the first place). When the key is turned off or the killswitch lanyard pulled, it creates an open circuit that directs the power from the b/y wire to a ground, killing the motor. So if there is a bad connection somewhere along the b/y wire the motor is still able to run because it?s receiving power from the ignition/alternator (and nothing happens to that power when it reaches the b/y wire?s dead end) ? but it can?t be turned off because the b/y wire is no longer able transfer to a ground.

Is this correct?

Also assuming the motor isn?t dieseling, is there anything else that could cause this condition other than an issue somewhere along the circuit described above? I?ve seen alternator back feeding mentioned as a possible culprit in other threads, but don?t know anything about it.
 
Last edited:

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
Don't take this as gospel since my books still say that you have two power packs, but normally the switches ground the black/yellow wire to kill the ignition. The kill switch and the ignition switch get there ground from the black wire. So if either circuit is open it looses it's ability to kill the power pack.
The ignition system receives its own power direct from the stator when the engine cranks.
BTW the newer engine with a single power pack show the same system.
 

rapishorrid

Seaman Apprentice
Joined
Apr 2, 2016
Messages
30
Found the problem. I worked back from the ignition with a multimeter until I found an open loop. Turns out the b/y wire was severed due to corrosion right where it connects to the engine side of the red connector (main wiring harness). I connected one end of a wire to the severed b/y wire, stuck the other end in the female side of the red connector, plugged the connector back together (over the new wire), wrapped the whole thing in electrical tape and voila - engine shuts off with the key and killswitch. Not sure if I should keep it like this or just get a new wiring harness for $100.

How hard is it to replace the engine side of the wiring harness? Seems simple, but I can't see how it connects to the power pack.
 
Last edited:

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
I'm still having trouble getting good information on your engine, but since no one else has chimed in. It looks like there's only five single wire connectors going from the main harness to the power pack. They should just unplug.
The whole thing may be behind a cover at the back of the engine. The voltage regulator/rectifier and a terminal block for the wiring may be there too.
 
Top