Engine doesn't turn off when switched to off

[thatguy]

I have a Yard Machine by MTD that will not turn off when I remove the key. I tested the ground wire and the wire that goes to the ignition coil for continuity and they all pass. I have also checked that continuity exists when the key is turned to the off position between the ignition coil and the frame and engine block and there is.

It is my understanding when the ignition wire it grounded it prevents the spark from generating thus killing the engine but it does not seem to be the case with mine. I have taken another jumper wire and connected one end to the ignition coil and the other to ground on the lawnmower with no effect. When the lawn mower is in the run position continuity does not exist between the ignition coil and ground.

I have purchased a new ignition switch but that changed nothing.

Any ideas???

Thanks!

 

[ILENGINE]

you said that you connected a wire directly to the ignition module and ground and still not shut off, is this correct. if so then the primary winding in the ignition module is broke and you will need replace the module.

i have seen this twice before so it is rare.

 

[reynoldston]

Don't worry about continuity so much. Electric has two polarity's positive and negative. At some location you are missing the negative, maybe between the engine and the chassis? A good multi-volt will give you this information.

 

[thatguy]

Yes, I ran a 14G wire and grounded the ignition module to the frame and the engine, while it was running, with zero effect. I'll replace the ignition module and let you know.

Thank you!

 

[thatguy]

Thanks ILENGINE!!!

Finally got my replacement ignition module and sure enough that was the problem. She is back to firing up and turn off.

I swear I always get the rare problems...