Motor will not turn off with switch. (1980 Johnson 25HP)

I have a 1980 25 hp Johnson J25TELCSA that will not shut off by pushing the stop button. I have read some posts from people with similar problems, but none of those have quite the same variables. I do not have a remote start. There is a push button for the START and a push button for the STOP. The motor fires up immediately and runs fine. When I push the STOP button, nothing happens.
The switch has two wires. One is bolted to ground on the power head using a coil bolt. The other goes into a three pin connector that connects to the power pack. One pin is the orange wire from the top coil, one is the orange wire to the lower coil and the other wire is the second wire from the STOP button that connects to a black and yellow wire.
I disconnected the switch and tested for continuity with a volt meter. The switch works fine. To test the yellow and black wire and by pass the switch, I removed the pin from the connector that leads to the switch wire. I inserted a conductor making contact with just the yellow and black wire. I grounded this conductor expecting the motor to turn off but nothing happened.
I pulled the three pin connector apart and the motor turned off. I’m at a loss here.

If the power pack were bad, would the motor run? Could it be the yellow and black wire is loose/disconnected inside of the power pack? How would I test this?

I would test your switch before anything. A simple continuity test will tell you if it is good or not

That was the first thing I checked. I took the switch completely off of the motor to isolate it. It works as it should.

Dying2fish said:

That was the first thing I checked. I took the switch completely off of the motor to isolate it. It works as it should.

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Look for a bad connection. Grounding ot the switch box kills the motor.

I have double checked all connections. All are secure. I verified that there is a good connection on the ground wire from the power pack to the power head. Everything seems to be connected properly.

If grounding the appropriate power pack wire doesn't shut it off, it's broken. Cannot meaningfully be serviced due to it being potted, but it's fairly cheap.

Thanks for the reply boatbear. I have ordered a new power pack, should be here today. I will post if it works or not.

I replaced the power pack and that fixed my problem. The motor now turns off using the shut off switch. Thanks for the suggestions.

(BTW, this is a tiller style motor for those interested in the problem and the fix.)