Kubota Z726 dies when I take foot off parking brake.

[RickB]

The OPC controller isn’t recognizing the seat switch signal. Seat switch, wiring or the OPC controller are possible causes. I can’t tell from here what the exact cause is so I said there is a fault in the circuit. A simple seat switch replacement might well be a waste of money. A blown fuse is also a possibility if you were adding wiring.

 

[Rowdy Redneck]

The OPC controller isn’t recognizing the seat switch signal. Seat switch, wiring or the OPC controller are possible causes. I can’t tell from here what the exact cause is so I said there is a fault in the circuit. A simple seat switch replacement might well be a waste of money. A blown fuse is also a possibility if you were adding wiring.

Thank you sir! Fuses are something I have a little more familiarity with so I'll check them out. I'll also check all the wiring as closely as I can in case something came loose.

 

[Rowdy Redneck]

Well, a little update. I went by Kubota and told the parts guys about the issue. They said it was worth trying a new seat switch and that I could bring it back if it didn't solve the problem. I asked about bringing the mower in but they said it would be a month before they could look at it. Back at home I tried the switch and it didn't work. I also looked at all the fuses and they seemed okay. I completely unhooked the light bar that we installed, since that was the only change made since things worked properly. That did nothing.

I don't know if it makes any difference, but when I ease off the brake pedal it only dies at the very end. That's frustrating because I always get my hopes up that it's working only to fail again.

To my simple mid this now seems like a wiring issue, though I don't know what would have caused the wires to go bad. Although the parts guy did mention sensors for the "handlebars", but I can't find any information about them online.

So I am at a bit of a loss. I realize I am in over my head but would like to defeat this beast. I have a multimeter but pretty limited understanding of how to use it.

 

[tomplum]

It could be a wiring issue, so look in the area of your light install and other areas which may have gotten pinched, a connector pulled off, etc. Checking the brake and position sensors for the bars with your multimeter, use the OHM setting. A 2 pole switch is either normally open or normally closed, a 4 pole switch many times has a pair of each. Putting your leads on the 2 terminals, then activate the switch and there should be a change. A 4 pole switch is basically 2 sets of terminals. Checks the same way, you just have to determine which 2.

 

[the old grind]

.. the parts guy did mention sensors for the "handlebars", but I can't find any information about them online.

I have a multimeter but pretty limited understanding of how to use it.

'Handlebar switches' are part of the o'all wiring setup. With many ZTRs the handles must be fully apart or the starter will not engage. BWTM! example: Our CC RZT50s have a second pair at handle bases to disengage the PTO/blades when backing up. Look for them all near the handlebar pivots. dovers may have to come off.

A 3-wire switch (vs paired terminals, eg: SPDT) is on or off to each terminal at whichever position, a selector switch. Don't let the terminals confuse you, or the VOM. The simplest meter will have OHMs. With battery disconnected and set to low ohm scale it's a great tester of any switch. (.. that has no more than one wire connected but another explain)

Connect the leads to pairs of switch terminals to determine which switch positions mean which (pairs) are 'open' or 'closed'. Alligator clips are your friend. I suggest that perhaps the brake pedal switch or a bar switch has gone South. Here's a wild thought. Either bar switch could cause the issue. Figure them both out and if they don't match one is surely toast. Any switch that pops out of its mounting won't function

Also, there's likely more than one ground for the harness beyond the main at the battery. I've added, reconnected, and replaced ground wires or straps 'just to be sure'. Ground all add-ons to chassis (vs thru' harness) and service main ground strap to frame as with battery post tabs. (y'all 'uns knew that)

 

[Rowdy Redneck]

Tomplum and Old Grind, thank y'all so much for the thoughtful and informative replies! I have been out of town for work for a few days so am only now able to reply. Tomorrow I will test things out and report back. I think my dad might be coming over tomorrow, and while he doesn't know any more than I do about these matters, another set of eyes will hopefully help. Thanks again guys!