ExMark won't stay running! Help!

[t-trucker]

I have a used ExMark that I mow our church grounds with. Model # LHP5223KC. It starts just fine, but when the "parking brake" is released, the mower dies. I've replaced all of the switches one at a time, no change. I've not replaced the ignition switch yet however. Any ideas? HELP!

 

[Lawnranger]

Most of the safety circuits work by providing a ground to the primary side of the coil(s) which kills the engine. Something on your mower is providing that ground and you will need a schematic to trace all the components in the safety circuit. Switches can be easily tested with an ohm/continuity tester so don't go buying any more switches until you properly test them. The ignition switch provides a ground through the "M" terminal when turned to the off position so most likely not the problem but always verify by testing. Again, you will need to find a schematic so you know what you are dealing with. Some machines use a module or a relay and these parts can create the symptom you are experiencing.

Sometimes a wire in the kill circuit is shorted to ground and you will have to trace every inch of wire to verify. Try wiggling/pulling on the harness while the engine is running and try different areas of the harness. Look very carefully where the harness bends around metal parts of the frame, etc.

The above are just some ideas to try and what I have done in the past when I have a machine doing the same thing.

Get your schematic out.