Challenger MT 455 proposed electronic lift control Modification

[Knivens894]

I have owned this 4 WD tractor since new. The three point lift electronics have been a real problem and continue to do so. Currently, the angle sensor has failed (again). I went on line to purchase another, only to find the part has been discontinued.

I am seriously considering just installing a rocker switch wired directly to the up and down solenoids to eliminate the computer from that system. The computer locks out the controls when any sensor gets out of its specified range, or the sensor fails. That can be a real pain at times when the system needs to be working correctly.

I am aware newer versions of this tractor went to a switch control. I am willing to give up draft control as long as the system works reliably. Has anyone out there made such a modification, and if you have would you please let me know of the adverse results such a modification might cause? My thoughts are the the angle sensor was installed to control the up and down limits of the draw bar, so the lift system would need limit switches to avoid hydraulically overloading with a straight wired solenoid control switch.

Does anyone have further thoughts or comments concerning this proposal?

 

[Cliffy]

Im a bit rusty on these old girls.
But for part try AGCO. Same tractor different colour.
Wiring and earths where the main cause of problems.
The wires weren’t taped in the conduit and rubbed through. Dont know what the french where thinking.
Loading up hydraulics is not an issue as the solenoids are momentary activated. So if you dead head it it will just dump pressure through relief valve.
I have rewired a different model to switched control. On that model the external switches worked the linkage without waking the controller and activated the solenoid directly.
I just tapped into wiring and installed monetary switches inside cab.

 

[Tyler d4c]

Im a bit rusty on these old girls.
But for part try AGCO. Same tractor different colour.
Wiring and earths where the main cause of problems.
The wires weren’t taped in the conduit and rubbed through. Dont know what the french where thinking.
Loading up hydraulics is not an issue as the solenoids are momentary activated. So if you dead head it it will just dump pressure through relief valve.
I have rewired a different model to switched control. On that model the external switches worked the linkage without waking the controller and activated the solenoid directly.
I just tapped into wiring and installed monetary switches inside cab.

And theres what makes this forum great! Good first hand experiance!

 

[Knivens894]

Cliff, I sincerely appreciate your reply. The factory installed system has been a constant pain, so I am perfectly fine with just an up-down switch.

When you said solenoids are "momentarily activated", is that internal to the solenoid, or is "momentary" created by the up-down rocker switch. Do I need to feed it with other than a 12 V supply? I have ordered an up-down switch to install in the hole where the system monitor flasher is currently.

Thank you again for your insights into this issue. The last parts I purchased for this machine were from JCB. JCB has apparently bought AGCO. They are both part of the same organization I am told.

Kirk

 

[Cliffy]

from what I understand, the mt455 is a 4255 massey Ferguson. Most parts will be interchangeable.
I havent heard about JCB purchase, but AGCO owns alot of brands. Fendt, **, valtra, gleaner, trimble challenger, fella ect.

Do the external switchs work on the mud guards?
I modified a 3400 **. I basically moved the external rocker switch inside and left all the controllers in place. The external switch over rode the linkage controller and powered solenoid.

For the rocker switch, i would use a momentarily activated switch rather then a detent switch. (** 3455 external rocker switch) This will prevent the linkage from dead heading if left on.

Im not sure if you can power the factory solenoid directly as it will be most likely proportional. I would measure voltage at solenoid. Most likely it will be 12v but may burn it out. I would give it a go but be prepared for a short life expectancy.

You could also purchase an off the shelf solenoid valve assembly. Hook hoses up and off you go.