4120 PTO safety override

[whitedogone]

The safety overide on my 4120 does not work. The seat switch seems to work OK as when I get off with the PTO engauged the tracor shuts off. But when I follow the procedure to override the safety and keep the thing running when off the seat, the tractor still shuts down. What do I need to check?

 

[JD755]

I know there has been some comment here about making sure you stay on the seat for two or three seconds after engaging the PTO. This is to let the seat delay (operator bounce) time out.

 

[whitedogone]

BTW, this tractor has the mid pto installed. Don't know if that changes anything or not.

 

[RoyJackson]

I know there has been some comment here about making sure you stay on the seat for two or three seconds after engaging the PTO. This is to let the seat delay (operator bounce) time out.

The manual calls out getting off the seat, then engage the PTO, which is how it's done on my old 4400 too.
I'm not sure why one would have to stay on the seat for two or three seconds....is the manual in error?

Using Rear PTO (Operator off Seat)

NOTE: The rear PTO can be engaged with the operator off the seat. The Safety Interlock System will stop the engine and all implements if the mid-PTO is engaged and the operator gets off the seat.
Engaging Rear PTO
1. Sit on operator痴 seat.
2. Move transmission to neutral position:
PowrReverser: Depress clutch pedal completely and move the transmission gear and range shift levers to the N (neutral) position. Move the reverser lever to the N (neutral) position.
eHydro: Move the range shift lever to the N (neutral) position.
3. Lock park brake.
4. Push all PTO engagement knobs to the disengaged/off position.
NOTE: The starter will not crank if the rear PTO knob is pulled to the engaged/on position.
5. Start the engine and adjust speed to 1500 rpm.
6. Get off the operator痴 seat.
7. Engage rear PTO:
Tractors without cab - Pull the rear PTO engagement knob to the engaged/on position.
Tractors with cab - Move the PTO selector lever to rearward position for rear PTO only. Pull the rear PTO engagement knob to the engaged/on position.
8. The instrument panel PTO engaged light will illuminate when the rear PTO is engaged.
9. The engine should continue to run.
10. Adjust the hand throttle lever forward to the desired speed for implement used.

 

[JD755]

You are correct Roy. I think what I was remembering was to not engage the PTO until you have been OFF the seat for a few seconds. Otherwise the seat delay thinks you are still on the seat. That does make more sense.

 

[jd110]

BTW, this tractor has the mid pto installed. Don't know if that changes anything or not.

Are you trying to get off the seat while the mid pto is on? The override only works for the rear pto.

 

[whitedogone]

Are you trying to get off the seat while the mid pto is on? The override only works for the rear pto.

Mid pto is NOT engauged

 

[whitedogone]

The manual calls out getting off the seat, then engage the PTO, which is how it's done on my old 4400 too.
I'm not sure why one would have to stay on the seat for two or three seconds....is the manual in error?

Using Rear PTO (Operator off Seat)

NOTE: The rear PTO can be engaged with the operator off the seat. The Safety Interlock System will stop the engine and all implements if the mid-PTO is engaged and the operator gets off the seat.
Engaging Rear PTO
1. Sit on operator痴 seat.
2. Move transmission to neutral position:
PowrReverser: Depress clutch pedal completely and move the transmission gear and range shift levers to the N (neutral) position. Move the reverser lever to the N (neutral) position.
eHydro: Move the range shift lever to the N (neutral) position.
3. Lock park brake.
4. Push all PTO engagement knobs to the disengaged/off position.
NOTE: The starter will not crank if the rear PTO knob is pulled to the engaged/on position.
5. Start the engine and adjust speed to 1500 rpm.
6. Get off the operator痴 seat.
7. Engage rear PTO:
Tractors without cab - Pull the rear PTO engagement knob to the engaged/on position.
Tractors with cab - Move the PTO selector lever to rearward position for rear PTO only. Pull the rear PTO engagement knob to the engaged/on position.
8. The instrument panel PTO engaged light will illuminate when the rear PTO is engaged.
9. The engine should continue to run.
10. Adjust the hand throttle lever forward to the desired speed for implement used.

Roy, I think that there are instructions for "operator ON seat" as well. Those are the ones I'm using. WDO

 

[RoyJackson]

Roy, I think that there are instructions for "operator ON seat" as well. Those are the ones I'm using. WDO

Per the Operator's Manual, those instructions are what you should be doing for off seat PTO work. I just copied and pasted from the Deere website.
They're the same as my Deere 4400 (Reverser transmission). I use the off seat operation 2-3 times during the mowing season (for a chipper).
I also engage the PTO at around 1000-1200 RPM.
BTW, after the range, gear and forward-reverse levers (on my 4400) are in neutral, I get off the tractor and start the engine while off the machine. If you try this, be very careful and ready to jump back in case the machine moves on you.

Try those instructions step by step (print them out when you try it, so you don't miss something). Double check each step as you go...especially the range selector in neutral.
Try it with no implement rigged to your PTO.
If the tractor still stops, I suspect one of your safety switches is malfunctioning.

 

[om21braz]

Like Roy states, follow the directions to the tee and you should not have any problems. I had to bring my operator's manual out and have it sitting in my lap the first time or two I wanted to run the pto w/ me off of the tractor (4120).

 

[RoyJackson]

Like Roy states, follow the directions to the tee and you should not have any problems. I had to bring my operator's manual out and have it sitting in my lap the first time or two I wanted to run the pto w/ me off of the tractor (4120).

Same here...

 

[whitedogone]

Like Roy states, follow the directions to the tee and you should not have any problems. I had to bring my operator's manual out and have it sitting in my lap the first time or two I wanted to run the pto w/ me off of the tractor (4120).

Been there........done that.

 

[RoyJackson]

Been there........done that.

OK...probably a bad safety switch. Machine still in warranty?

 

[whitedogone]

no, which switches are there that control this?

 

[RoyJackson]

no, which switches are there that control this?

As you know (from my previous posts on this thread), I have a 4400 so I don't have a specific answer for you.

First thing I'd check would be the operator presence switch under the seat. Before you jumper anything...have a friend stand on the operators' station....go through the "off seat" process and engage the PTO. Your friend is to set on the seat if the engine starts to die. If the engine picks up and continues to run, the seat switch is probably good. There is a neutral safety switch and a PTO switch, but I don't know where they're located on a 4120.
As far as other switches or sensors, this is a good question for your dealer. They may even provide a copies from the applicable sections of the service manual so you can locate those switches or sensors.