I do not have the seat switch bypassed. It works like normal. I will look and see if it is 2 wire or 4 wire. I think it is the 4 wire but will check to be sure.
Thanks for all the reply's.
Thanks for all the reply's.
MX5000D safety circuit problem
- Thread starter cabbott
- Start date
Here is a schematic from another kubota tractor, while it may not be the same as yours it gives you some ideas on how the general logic of the circuit works.
First look at the PTO and HST switches, the top line of the switches goes to the "engine RUN" part of the circuit, the bottom line of the same switches goes to the "engine START" part of the circuit.
Looking at the lower START circuit, you can see that the starter motor will not operate if you have the PTO engaged, or the transmission NOT in neutral.
However, once the engine is started and running, you can select drive and/or PTO, AS LONG AS YOU ARE SITTING IN THE SEAT.
The seat switch.
Looking at the top line of the seat switch, when the seat switched is CLOSED by SITTING, power goes to the OPC timer on 2 pins of the timer (wires 20Y & 20RW), and since it senses you SITTING in the SEAT it should output power on wire 20R, powering the Timer Relay, which powers the fuel solenoid, allowing the engine to continue to run as long as someone is SITTING in the seat. This happens no matter what gear or whether the PTO is selected.
Now looking at the top line of the PTO and HST switches (the engine RUN part), if these are both CLOSED, then power also feeds through them and powers/joins the same wire 20R from the OPC Timer, which goes to the Timer Relay, allowing the engine to continue to run.
So the engine will continue to RUN ONLY, - IF you are SITTING in the SEAT, - OR if the transmission is in NEUTRAL AND the PTO is NOT selected and you are out of the seat.
You have bypassed (shorted/bridged) both the PTO and Neutral safety switch, so power flows out this wire and allows the engine to run, no matter what.
Why is this necessary, because power is not coming from the OPC Timer to the Timer Relay.
So either the OPC Timer is not getting power from the seat switch, or the OPC Timer is faulty, or there is a break in the wire between the OPC Timer and the Timer relay.
Hence the reason I suggested bridging out the seat switch.
The seat switch is powered from the same source fuse as the PTO/Neutral switches "IN THIS DIAGRAM", but may not be on your tractor. Check all of your fuses (hopefully you would have already), check to see that you are getting power into and out of the seat switch when it is activated for the SITTING position, check to see that you then get power on both pins of the OPC timer, and power out of the OPC timer. (If yours has similar number of wires as this diagram). If you have power exiting your OPC Timer, ensure it is arriving at the Timer relay, without the PTO/Neutral switches shorted out
First look at the PTO and HST switches, the top line of the switches goes to the "engine RUN" part of the circuit, the bottom line of the same switches goes to the "engine START" part of the circuit.
Looking at the lower START circuit, you can see that the starter motor will not operate if you have the PTO engaged, or the transmission NOT in neutral.
However, once the engine is started and running, you can select drive and/or PTO, AS LONG AS YOU ARE SITTING IN THE SEAT.
The seat switch.
Looking at the top line of the seat switch, when the seat switched is CLOSED by SITTING, power goes to the OPC timer on 2 pins of the timer (wires 20Y & 20RW), and since it senses you SITTING in the SEAT it should output power on wire 20R, powering the Timer Relay, which powers the fuel solenoid, allowing the engine to continue to run as long as someone is SITTING in the seat. This happens no matter what gear or whether the PTO is selected.
Now looking at the top line of the PTO and HST switches (the engine RUN part), if these are both CLOSED, then power also feeds through them and powers/joins the same wire 20R from the OPC Timer, which goes to the Timer Relay, allowing the engine to continue to run.
So the engine will continue to RUN ONLY, - IF you are SITTING in the SEAT, - OR if the transmission is in NEUTRAL AND the PTO is NOT selected and you are out of the seat.
You have bypassed (shorted/bridged) both the PTO and Neutral safety switch, so power flows out this wire and allows the engine to run, no matter what.
Why is this necessary, because power is not coming from the OPC Timer to the Timer Relay.
So either the OPC Timer is not getting power from the seat switch, or the OPC Timer is faulty, or there is a break in the wire between the OPC Timer and the Timer relay.
Hence the reason I suggested bridging out the seat switch.
The seat switch is powered from the same source fuse as the PTO/Neutral switches "IN THIS DIAGRAM", but may not be on your tractor. Check all of your fuses (hopefully you would have already), check to see that you are getting power into and out of the seat switch when it is activated for the SITTING position, check to see that you then get power on both pins of the OPC timer, and power out of the OPC timer. (If yours has similar number of wires as this diagram). If you have power exiting your OPC Timer, ensure it is arriving at the Timer relay, without the PTO/Neutral switches shorted out
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Thanks for the reply. This gives me a starting point to trouble shoot my problem. This is the first complete schematic I've seen on safety circuit. I will verify that my tractor is wired the same way. Again Thank you for providing schematic.