Small Engines (Lawn Mowers, etc.): not safety switch or ignition, safety switches, stipped

Question
QUESTION: hi John , i had to ask new
question it said too many follow ups
dont they know it sometimes takes a few
to fix a lawn tractor ??
anyway its  a simplicity 4212 ( model 1691427) 12 hp electric start
as i said before i got it started by removing
the coil kill wire
so i checked the kill safety switches as you
advised but all seem ok
actually when unplugged the engine doesnt
turn at all , if i jump the connector
it turns but not start
i put the old ignition switch back ( it was changed
due to key stipped) on and tried
it, same thing. so it appears the ignition switch
is good as all three of the safety switches
i removed the coil kill wire and check with a meter
with key in off position it reads about 50 ohms
when i turn the key on it goes to 460 ohms
the engine starts at a bump of the key (thanks to
your advise on how to tune the carb)when the coil kill wire
is removed but with its plugged into coil it just cranks
what else can ground the kill wire if the saftey and ignition switches are ok??
I know im close now to having it perfect so thanks
for all your help
john L

ANSWER: Hi John:

LOL  Sorry About the Too Many Questions Problem. The PC Techs Really Do Not Understand Lawn Equipment. LOL. The Harness has a Bad Wire that is Causing the Ground Problem. I Suggest you Replace the Cut Off Wire from the Coil to the Ign Switch and Tape the Old Wire Off and Out of the Way. Simple and Easy. Tracing the Harness Takes a Lot of Time. The Coil is Grounded on 1 Side to Function and Fire the Spark Plug, and Grounded on Both Sides to Stop the Fire to the Spark Plug. Make Sure you attach the New Wire to the Ign Switch Lug that is Grounded Only when the Switch is in the Off Position. Use the Electrical Diagram at the Site Addy I Sent you to Assit you in Running the New Wire. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

---------- FOLLOW-UP ----------

QUESTION: Hi John , I think ive found it , it seems the culprit is the interlock module , unable to find one ill just rewire the system using a relay making all the safety switches work in series.
thanks for your help youve been great . soon as you described how the coil works the rest was easy
thanks again,john L

Answer
Hi John:

Great!! I am Glad I Could Get you on the Right Track to Locate and Repair the Cause of the Problem. Darn Pesky Interlock Module. I Forgot about that. I Apologize for the Lapse in Memory. It is Rare for these to Go Bad and I Tend to Dismiss them as Not being on the Mower at All. I have Seen 2 that were Bad in the Years Since the OEMs have been Putting them on the Mowers, but I Usually Do as you are Going to Do When It Goes Bad. Install a Relay and have the Safety Switches Function in a Series Type Circuit. Till Next Time. May All Your Mechanical Problems be SMALL ONES and May the All Mighty Bless You and Yours. Thanks Again.

Best Wishes and Good Luck

Respectfully

John