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Simplicity Riding Mower - No Spark

gus9246's Avatar

Join Date: Oct 2008
Posts: 2

10-22-08, 10:06 AM   #1  
Simplicity Riding Mower - No Spark

Good Afternoon,

Troubleshooting a Simplicity Broadmoor 15hp Hyrdo. 1994 model with Briggs & Stratton 28Q777 0112-01.

I have been reading some threads on diagnosing a no spark condition.

I removed the kill wire going to the coil. I have spark when that wire is removed. Because I have spark with the kill wire off. It seems that I have a problem with a safety switch.

Could the problem also be with the ignition switch? When I trace the wires I think that I have the following components that I need to consider (PTO switch, clutch/brake pedal, transmission lever Neutral switch, seat switch and ignition switch).

I also noticed that the following lights come on. Neutral light is on when in Neutral and goes off when moved away, seat light comes on when depressed and goes off when released, PTO light comes on when raised and goes off when in down position. And when the clutch pedal is up the start won't engage. Does that mean that these are not causing the problem? That makes me wonder if the ignition key switch could be the problem.

Any advise on how to trouble shoot which switch is causing the no spark condition.

Thank You,

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cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567

10-23-08, 01:23 AM   #2  
To troubleshoot the system, use an ohmmeter to check the switches until you find the one that is not breaking the connection to ground when activated. The indicator lights don't necessarily show that each switch is working properly, since most safety switches have multiple circuits that get switched. Seat switches and tranny neutral switches, however, usually only switch one circuit.

"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

gus9246's Avatar

Join Date: Oct 2008
Posts: 2

10-23-08, 09:05 AM   #3  
Ohmeter for PTO and Tranny Neutral Switch

Cheese - Thank you for the help.

That seems pretty clear. And I can probably rule out the seat and the clutch switch. Those only have two wires going to them. And the lights come on when activated.

My tranny neutral switch has mulitple wires (5) going to it. PTO switch has 4 wires going to it. I think I need to identify the circuit for each of these that goes to the kill wire.

There are a couple of splices (look like factory) that confuse me when trying to trace the wires. Any idea of how to get a wiring diagram? Will take a crack at it again.

Any thoughts on the ignition switch. Can I rule that out or is there a simple way to test it. If I traced the wires correctly there is a purple/black wire on the kill circtuit, going to the ignition switch.

Thank You Again

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