View Full Version : John Deere GX345, what is this thing??

08-21-2009, 09:45 AM
Hey guys,

I'm working on a John Deere GX 345 for a friend. When he brought it to me it was not firing.
Checked the coils and wires for obvious things, and traced both coil hot wires back to "something" about the size of a shotgun shell and 2 inches long that is (was) zip tied to the side of the engine.
This "thing" has 5 or 6 wires connected to it, hot and ground, one to the ignition control box, and one to each coil. (I think that's all of them, maybe one other, not with me right now)
I thought it might be the overturn kill switch, but removing it and laying it on it's side does not kill the engine.
I unpluged all the wires and tried to ohm it out, but it didn't compute. When I plugged it back in it fired and ran.
He said it would sometimes sputter when driving across rough ground, and at first I could make it sputter by tapping or shaking this thing, but after 2 hrs of mowing it's fine and I can't make it sputter anymore.
Is this a sophisticated overturn kill switch, or something else entirely, like a replacement for the diode kill harness maybe? I would try to bypass it, but I didn't want to fry the ICM.
Thanks for any info or ideas.

08-21-2009, 06:51 PM
That little part is a time delay module. Im sure you noticed when shutting the key off, the engine runs for a few seconds then dies. It's supposed to help prevent backfiring. They are notorious for going bad. The John Deere part number is--AM128906.

08-21-2009, 11:18 PM
Thanks JHugh.
Do you know if it's possible to just bypass this switch?

08-21-2009, 11:38 PM
I never tried to bypass it due to the risk of ruining ignition parts or other electric components. Those parts are expensive. I don't think the part is that expensive. I was thinking the cost is about $20-25.

08-23-2009, 10:32 PM
Yep, it can be bypassed. Hook everything together excepc the red wire.
In fact, it's just a "plug and play" situation, they will all plug into one of the already used connectors, just 4 wires.
ANd hey, thanks for the help!