It just shut down…

[SadFace]

B2650, 300hrs. I was mowing when the tractor shut down, like the ignition switch was turned off, will not start. I troubleshot the seat and neutral switches and fuses. All okay, no blown fuses. Battery indicator and the glow plug indicator light up with the key and I hear a click. Called my dealer for estimate….OUCH! I need to do some more troubleshooting.

 

[Pawnee]

On the surface it sounds like you have 2 problems.
1/ Will not run
2/ Will not crank

However:
Since it stopped running it may have sensed an 'illegal interlock' condition in which case it may not run or crank.
It's possible a connector away from the switches has got disconnected or a wire broken or pulled out.

I'd be looking for where a stick may have poked up and done something.

 

[Henro]

On the surface it sounds like you have 2 problems.
1/ Will not run
2/ Will not crank

Confirm whether it will NOT crank and therefore not start, or if it cranks and does not start.

Being VERY specific in what is happening will get you the best advice.

Unlikely you have two simultaneous problems.

 

[OrangeKrush]

Sounds like an electrical issue, probably jarred loose a wire.

 

[IdahoNative]

Same thing happened to me. Turns out a pressure plate finger broke and lodged between the flywheel and the housing. Stopped it dead immediately. Would not do anything.

 

[SadFace]

So, this is what I found...

I tested all 4 OPC switches, all good. Found OPC 5amp fuse blown. Replaced fuse. Fuse keeps blowing when the tractor is under a load. Example's, from rest, start to drive up an incline blow the fuse. While mowing normal, went through a tall patch of grass putting a normal strain on the engine, blow the fuse. When I was backing up into my barn, went up a slight incline the fuse blows. I verified the wiring hardness for any damages, visually. Hardness looks clean, no damages. I take good care of my tractor. Should I replace the OPC switches? How would the dealership troubleshot something like this?

 

[Henro]

So, this is what I found...

I tested all 4 OPC switches, all good. Found OPC 5amp fuse blown. Replaced fuse. Fuse keeps blowing when the tractor is under a load. Example's, from rest, start to drive up an incline blow the fuse. While mowing normal, went through a tall patch of grass putting a normal strain on the engine, blow the fuse. When I was backing up into my barn, went up a slight incline the fuse blows. I verified the wiring hardness for any damages, visually. Hardness looks clean, no damages. I take good care of my tractor. Should I replace the OPC switches? How would the dealership troubleshot something like this?

Just a thought, but under load you are probably pushing the HST directional pedal further than if just going along at a slow pace on level ground.

If you would be in the mode that works...sounds like that is level ground with not a lot of HST pedal movement, and would quickly push the pedal down, will the fuse blow?

Sounds like it could be an issue with the switch that senses the HST pedal position. Check the wiring going to that switch, if the fuse blowing feeds it.

Another idea might be to physically move the wires in the harness and see if the fuse blows, while the tractor is running, in neutral of course.

Others might come up with different helpful suggestions...

 

[Pawnee]

You have narrowed the problem down a fair bit already.
Unless the dealer has an electrical whiz in the service department which is rare, they will likely start replacing things and hope for the best.

Loading up a diesel engine doesn't increase electrical load.
However, it will torque against the mounts and might move some of the wiring harness which could be rubbing on something and making a short.

Pretty much what Henro has already said.

In case you are tempted to put in a bigger fuse, bad idea.
Once you find this problem, it will seem simple.

 

[GreensvilleJay]

I agree with Henro... need to check very,very carefully around the HST pedal.
Have someone 'play farmer' and slowly rock the HST pedal while you're under there to SEE what's moving around. Be sure to have lots of light and wiggle any wires or harnesses.
Hopefully you don't wear bifocals...they are a real PITA 'down below'.....

 

[Dave_eng]

Henro's advice is excellent.
You could jack the rear of the tractor and see if it is HST pedal position or grade
Dave

 

[Dave_eng]

I agree with Henro... need to check very,very carefully around the HST pedal.
Have someone 'play farmer' and slowly rock the HST pedal while you're under there to SEE what's moving around. Be sure to have lots of light and wiggle any wires or harnesses.
Hopefully you don't wear bifocals...they are a real PITA 'down below'.....

To Jay:
Ask your eye glass provide for "Tradesman" lenses. These have a bifocal portion at the top of the lens as well as the bottom so you dont have to tilt your head back to see above you.
Dave

 

[SAR Tracker]

With engine running, trans in neutral, RPM's at normal level for what you'd be doing, move the HST directional pedal. That would confirm or eliminate anything to do with the pedal, I'd think.

 

[RBsingl]

The 5A OPC/panel fuse feeds several circuits including the OPC.

If you have a meter which measures resistance, disconnect the negative battery lead and with the meter set to measure resistance between the 5 amp fuse output side and ground:

Inspect and manipulate the wiring around the seat, HST, PTO clutch, and PTO select switches while looking for the meter to indicate sudden decreased resistance to ground. There is also a "bi-speed" turn switch fed directly by this 5 amp fused circuit, I have no idea what that switch does.

Rodger

 

[Henro]

The 5A OPC/panel fuse feeds several circuits including the OPC.

If you have a meter which measures resistance, disconnect the negative battery lead and with the meter set to measure resistance between the 5 amp fuse output side and ground:

Inspect and manipulate the wiring around the seat, HST, PTO clutch, and PTO select switches while looking for the meter to indicate sudden decreased resistance to ground. There is also a "bi-speed" turn switch fed directly by this 5 amp fused circuit, I have no idea what that switch does.

Rodger

Another way to accomplish the same goal is to replace the fuse with a 12 volt light bulb. Watch the bulb while moving the wiring. If it lights, you have discovered there is a short in the wiring.

Then you start to zero in on where the short is. The light bulb is handy if you only have two hands. I have not done this myself, but would if needed. I always seem to work by myself.

 

[RBsingl]

Another way to accomplish the same goal is to replace the fuse with a 12 volt light bulb. Watch the bulb while moving the wiring. If it lights, you have discovered there is a short in the wiring.

Then you start to zero in on where the short is. The light bulb is handy if you only have two hands. I have not done this myself, but would if needed. I always seem to work by myself.

The only concern I have with this approach is when the fault/short isn't present, the electronics (including the OPC box) are going to be fed with a voltage greater than 0 but less than normal operating voltage since 12 volts will divide across the bulb and the rest of the circuits as a series voltage divider. Some digital circuits do odd things when fed with a voltage level that isn't either 0 or normal supply voltage. Usually it just causes a temporary glitch but that OPC box is pretty pricey and I wouldn't want to take a chance on damaging it.

Rodger

 

[Henro]

The only concern I have with this approach is when the fault/short isn't present, the electronics (including the OPC box) are going to be fed with a voltage greater than 0 but less than normal operating voltage since 12 volts will divide across the bulb and the rest of the circuits as a series voltage divider. Some digital circuits do odd things when fed with a voltage level that isn't either 0 or normal supply voltage. Usually it just causes a temporary glitch but that OPC box is pretty pricey and I wouldn't want to take a chance on damaging it.

Rodger

I don’t think this is a concern, because the 12 volt supply remains 12 volts, whether it lights the light bulb or doesn’t.

So the the light bulb being there makes no difference, and likely is less disruptive as far as transient voltages go, as compared to what might happen when an actual fuse blowing event occurs.

Still, no one can deny that making resistance measurements will offer a nearly zero chance of transient voltages at all, at least in the practical world .

 

[RBsingl]

The difference occurs because the OPC and gauge panel (both have parts fed from this fuse) are drawing some current in normal operation.

Unlike the fuse, there is voltage drop across the lamp when the OPC and panel are drawing normal operating current; they are in series with the lamp. If there was no current draw by those circuits, then they would see the full 12 volts but as soon as they start drawing current then the lamp filament acts as a resistive voltage divider.

Think of putting two identical 12 volt bulbs in series and feed the first 12 volts with the second lead of the second bulb grounded, if the second bulb is open you would measure 12 volts to ground at the output side of the first bulb and it would not illuminate. But if both bulbs are intact, then the 12 volts will divide equally with 6 volts appearing across each 12 volt bulb causing them to glow dimly.

In this case the circuitry (OPC and gauge panel) downstream from the test bulb is like the second 12 volt bulb and the voltage across the OPC (and gauge panel) will be less than 12 volts and dependent upon the current it tries to draw.

It PROBABLY won't hurt anything but I have no idea what circuitry is used inside the OPC and how it would respond to being fed far less than its normal 12 volts. With old style relays, switches, etc. it wouldn't matter but with a lot of integrated circuits when you are in the gray area between normal and no voltage unexpected events can happen.

Rodger

 

[Henro]

The difference occurs because the OPC and gauge panel (both have parts fed from this fuse) are drawing some current in normal operation.

Unlike the fuse, there is voltage drop across the lamp when the OPC and panel are drawing normal operating current; they are in series with the lamp. If there was no current draw by those circuits, then they would see the full 12 volts but as soon as they start drawing current then the lamp filament acts as a resistive voltage divider.

Think of putting two identical 12 volt bulbs in series and feed the first 12 volts with the second lead of the second bulb grounded, if the second bulb is open you would measure 12 volts to ground at the output side of the first bulb and it would not illuminate. But if both bulbs are intact, then the 12 volts will divide equally with 6 volts appearing across each 12 volt bulb causing them to glow dimly.

In this case the circuitry (OPC and gauge panel) downstream from the test bulb is like the second 12 volt bulb and the voltage across the OPC (and gauge panel) will be less than 12 volts and dependent upon the current it tries to draw.

It PROBABLY won't hurt anything but I have no idea what circuitry is used inside the OPC and how it would respond to being fed far less than its normal 12 volts. With old style relays, switches, etc. it wouldn't matter but with a lot of integrated circuits when you are in the gray area between normal and no voltage unexpected events can happen.

Rodger

I see no positive reason to debate this.

Fact is that the wiring leading up to the fuse is sized to carry the load the fuse protects. The light bulb, if properly sized, will no exceed this capacity.

Anyway, I do understand the theory...

Let's let the OP hopefully solve his problem without too much pain in the process...or confusion caused by us debating a theoretical possibility...

 

[SadFace]

It’s taken me a long time to get back with everyone. Here’s where I am at, I carefully tested all the safety switches and the wires the best I could. I get no shorts to ground, switches change state every time. The only difference is I’m not at operating temperature. Could it be the OPC control module?

 

[SadFace]

Forgive my ignorance, I have two similar looking modules. Which one is the OPC?