My OPC fuse on my 2650 keeps blowing. If I replace the blown 5 amp OPC fuse, it starts fine. If I try to move, or reverse direction, the fuse blows again. If it is not moving, it starts and runs fine. Whether I am sitting in the seat or not. If I push the forward foot pedal, it will move, but if I reverse direction, the fuse blows. I don't see any frayed wires under the seat. Going through a lot of 5 amp fuses. Any help would be appreciated.
B2650 OPC fuse keeps blowing
- Thread starter Garse
- Start date
I will start by pointing out I am NOT a B2650 expert.
The info I have comes from this WSM. Make certain this is your tractor!
Your tractor is more complicated than one with basic safety switches.
You have an Operator Presence Controller (OPC) which receives input from a variety of safety switches and, using its built in logic, determines if the engine can be started, continue to run , have the pto engaged.
This photo shows what the OPC looks like and where it is on your tractor.
This next schematic is the wiring diagram for the OPC and its related switches.
I am assuming the fuse which keeps blowing is the one in the red circle, #3.
As I study the wiring, I see that the fuse which keeps blowing is the one which, first feeds the OPC, next provides power for the safety switches which feed the OPC and provides power for the switching of the engine stop relay.
I believe it also provides the OPC with power that it can send or cut off to the engine stop system. (relay and solenoid).
The engine stop system has its own 30 amp fuse #2 but the switching of the engine stop relay comes from the 5 amp fuse through the OPC.
Since your engine starts and runs properly and only when you move the HST pedal does anything happen such as the fuse blowing, please advise if the engine continues to run even with the fuse blown.
Another thought which comes to mind is to remove the engine stop solenoid #11 to see if the fuse still blows.
Can you stop the engine using the key switch: 1- before the fuse blows or 2- after the fuse blows?
Dave
The info I have comes from this WSM. Make certain this is your tractor!
Your tractor is more complicated than one with basic safety switches.
You have an Operator Presence Controller (OPC) which receives input from a variety of safety switches and, using its built in logic, determines if the engine can be started, continue to run , have the pto engaged.
This photo shows what the OPC looks like and where it is on your tractor.
This next schematic is the wiring diagram for the OPC and its related switches.
I am assuming the fuse which keeps blowing is the one in the red circle, #3.
As I study the wiring, I see that the fuse which keeps blowing is the one which, first feeds the OPC, next provides power for the safety switches which feed the OPC and provides power for the switching of the engine stop relay.
I believe it also provides the OPC with power that it can send or cut off to the engine stop system. (relay and solenoid).
The engine stop system has its own 30 amp fuse #2 but the switching of the engine stop relay comes from the 5 amp fuse through the OPC.
Since your engine starts and runs properly and only when you move the HST pedal does anything happen such as the fuse blowing, please advise if the engine continues to run even with the fuse blown.
Another thought which comes to mind is to remove the engine stop solenoid #11 to see if the fuse still blows.
Can you stop the engine using the key switch: 1- before the fuse blows or 2- after the fuse blows?
Dave
Thanks, Dave for all the Electrical info. Yes, that is my tractor. The diagrams are quite informative. Answers to some of your questions: 1. When the fuse is blown - the engine does not run at all and can't be started. 2. When I replace the fuse and the engine is running - I can turn the tractor off using the key.
Only when I touch the HST, will it quit (reverse is real touchy to blow it).
I found the HST solenoid under the tractor and it seems pretty easy to replace. I'm going to try that first, if I can find the part.
I may try just disconnecting the solenoid and see if everything works. I'll let you know.
Thanks again,
Gary
Only when I touch the HST, will it quit (reverse is real touchy to blow it).
I found the HST solenoid under the tractor and it seems pretty easy to replace. I'm going to try that first, if I can find the part.
I may try just disconnecting the solenoid and see if everything works. I'll let you know.
Thanks again,
Gary
Gary
Do not be fooled thinking the obvious thing relates to the HST switch.
It may be what the OPC is doing when it receives the signal that the machine is about to move (via the HST pedal switch) that blows the fuse.
From the wiring diagram, it is obvious that the various safety switches are just turning on or off a 12 volt signal to the OPC. Unplug the HST switch wiring but then, after the tractor is running, jump the contacts in the wiring harness.
The OPC is likely smart enough to detect an open circuit so when you unplug it and when you jump it may be important in your trials.
Other forum members have discovered the OPC was faulty
Good luck and plse report back either with more questions or the fix.
Dave
Dave,
Thanks again. I believe there is a short in the Neutral Safety Switch (activated when you move the HST pedal. When I disconnected the switch, replaced the 5 amp fuse, turned the key, everything looks normal (Panel) but the starter won't engage. So, I tried jumping the connections between the disconnected neutral safety switch connector. Replaced the fuse, and started the tractor as normal. pressed the HST pedal forward and back. It works. So, now the neutral safety switch is taken out of the inputs to the OPC. Hopefully, I can complete my snow removal today and order a new switch.
Thanks again,
Gary
Thanks again. I believe there is a short in the Neutral Safety Switch (activated when you move the HST pedal. When I disconnected the switch, replaced the 5 amp fuse, turned the key, everything looks normal (Panel) but the starter won't engage. So, I tried jumping the connections between the disconnected neutral safety switch connector. Replaced the fuse, and started the tractor as normal. pressed the HST pedal forward and back. It works. So, now the neutral safety switch is taken out of the inputs to the OPC. Hopefully, I can complete my snow removal today and order a new switch.
Thanks again,
Gary
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Reading this for the first time.....I came to the same conclusion - a short to ground somewhere, either in the harness or the switch or somewhere.
Let us know what that switch costs and if the new one fixes it !
or will there be a new one?
I plowed snow for about 2 hours with no problem. I took my remaining three, 5 AMP fuses and a FIRE EXTINGUISHER! No problems though. I can run with the Neutral Safety Switch bypassed, but I will order one soon. I hope this helps anyone else with this, or a similar problem. Particular thanks to Dave! I printed out the OPC electrical schematic and stuck it in my manual just in case the OPC continues to be a problem.
Thanks again,
Gary
Thanks again,
Gary
Had the exact same problem. Changed the neutral switch and all better.
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Something to consider regarding fues/C.B.s that "blow" or "pop">
When the fuse blows...it means the circuit has conducted more current than for which the wire and it's insulation is designed. As the "short" activates, the excess current heats up the wire (and it's insulation) and the fuse ..which melts the fuse (or heats up the thermal-switch inside the C.B. and "pops" it.)
Repeatedly replacing that switch or repeatedly resetting that CB ***8230; repeatedly abuses that wire and it's insulation. Done to excess the wire may be permanently damaged as well as any appliances connected to it. So it is not good practice to continually replace fuses/re-set breakers without recognizing that permanent damage may occur in that circuit to the wire and/or appliances. It's better practice to investigate the short by other methods than merely replacing fuses, etc.
Hope this is helpful.
When the fuse blows...it means the circuit has conducted more current than for which the wire and it's insulation is designed. As the "short" activates, the excess current heats up the wire (and it's insulation) and the fuse ..which melts the fuse (or heats up the thermal-switch inside the C.B. and "pops" it.)
Repeatedly replacing that switch or repeatedly resetting that CB ***8230; repeatedly abuses that wire and it's insulation. Done to excess the wire may be permanently damaged as well as any appliances connected to it. So it is not good practice to continually replace fuses/re-set breakers without recognizing that permanent damage may occur in that circuit to the wire and/or appliances. It's better practice to investigate the short by other methods than merely replacing fuses, etc.
Hope this is helpful.
Replace the PTO safety switch, and possibly the neutral safety switch. I've had to do several of them, mostly pto switches. Most of the time when you wiggle it to unplug the harness, you'll find that the switch is like loose within itself.