This is a weird one...

I own a Craftsman YT4000 (917.288561) lawn tractor. After doing the annual maintenance (new plugs, new oil, new filters) I decided to also vacuum built up lawn clippings out of the engine compartment.

After I did that, it would not crank. It appeared dead as a doornail. After monkeying with it for 10 minutes I finally discovered it would crank if I turned the headlight switch on. Weird.

Right now, the mower operates normally with the headlights on, EXCEPT the lights don't actually turn on anymore. Weird.

After I start the mower with the headlights on, if I flip the switch to the off position the engine still runs, but the pressure seat switch appears to be disabled at that point. I can get off the seat and the engine will still run. Weird.

So my conclusion so far is that I shorted something out when I vacuumed the engine compartment. And somehow the headlight circuit is jumping it so everything operates normally.

Any ideas where the short could be? Any insight would be appreciated.

 

Lol... sounds like you don't need a mechanic, you need a priest.

I'd look for ground wires that might have gotten knocked loose. Bad grounds can do weird things. I can't fathom how turning the lights on would have any play at all in any operation of the mower though, bad ground or not.