Massey Ferguson 1250 (1998) Won’t Start

[Mwc1]

Good morning. I recently bought a MF 1250 that will not start. It can be jumped at the starter to get it running. The dash lights come on when the key is turned on. The preheat for the glow plugs does not work and the only way to kill the engine is to put it in gear and pop the clutch. Does this sound like a safety switch issue or is the ignition switch bad? Thanks in advance for any help.

Mark

 

[oldnslo]

I am not familiar with wiring on MF 1250 but I would suggest getting a test light or volt meter to check where you have power in the circuit and where you do not have power in the circuit. Doubt a safety switch would have anything to do with glow plug circuits.

 

[Roadworthy]

You may have two different issues. If you turn the key to the start position and get no response you may not be satisfying a safety switch. That may be the seat, clutch, PTO, gear selector, or something else - even a lack of voltage getting to the starter solenoid. If turning off the key won't stop the engine see if it has a fuel shutoff solenoid. A defective ignition switch is not out of the question, either. A bit of further troubleshooting is in order.

 

[Harry in Ky]

I have a reprint of the 1260 service manual (much the same tractor) that has a wiring diagram covering the 1240, 1250, and 1260. It's pretty fine print and hard to follow, but If you like I can work with you on it, and maybe get you sorted out.

 

[Mwc1]

Thanks for the replies. Harry in Ky does your manual show the locations of the safety switches? I need to buy the parts and service manuals but haven’t done it yet.

 

[IndyJay]

What year?
Can you hear the stop solenoid actuate and the lp fuel pump run when you turn the key on? I had similar starting issues with mine and it was the switch.

Does your injection pump get lubricated from the engine or does it have it's own sump? If it is not the ignition switch it may be a stuck rack in the injection pump. I had that issue where if the governor kicked in, it put the rack in a bad spot and it would run away. Had to put it in high gear and dump the clutch to kill it.

Hopefully it is just the switch.

 

[Harry in Ky]

Thanks for the replies. Harry in Ky does your manual show the locations of the safety switches? I need to buy the parts and service manuals but haven’t done it yet.

The only switches I see in the diagram are on the clutch pedal and the PTO switch/lever. Trying to make sense of a fine line, tiny print diagram with limited eyesight is sketchy at best, but as I see it the key "on" position supplies power to/through the PTO switch, then through some various harness connectors through the clutch pedal switch to the start relay coil circuit and then to ground. That relay is energized whenever the key is on and the PTO is off. The start signal ( pin/terminal 50) from the key switch "start" position leads to/through the start relay and then to the starter itself. If the relay is not energized the start signal stops there and won't reach the starter.

The injection pump stop solenoid works with the engine stop timer relay. The stop solenoid (at least to my knowledge) is spring loaded to the run position. If the engine turns over it will start. When you turn the key switch "off", that triggers the timer relay which supplies power to the stop solenoid and kills the engine. After a few seconds the timer shuts off, and the solenoid goes back to run mode. It will stay there until the key is cycled on and back off again. If the system isn't working for whatever reason, you can manually trip the shut off linkage to kill the engine, you just need to get off, remove the engine side cover to get to it.

At one time I knew those tractors pretty well. I was with a Massey dealership back when they were sold new.

 

[Mwc1]

What year?
Can you hear the stop solenoid actuate and the lp fuel pump run when you turn the key on? I had similar starting issues with mine and it was the switch.

Does your injection pump get lubricated from the engine or does it have it's own sump? If it is not the ignition switch it may be a stuck rack in the injection pump. I had that issue where if the governor kicked in, it put the rack in a bad spot and it would run away. Had to put it in high gear and dump the clutch to kill it.

Hopefully it is just the switch.

It’s a ‘98. When I turn the key to preheat nothing happens and when I turn the key to start nothing happens. The on position lights up the gauges and a couple of idiot lights. When I try to start it all of that shuts off. There’s no sounds or movement from anywhere else. I’m hoping it’s just the ignition switch. Does anyone have the part number for it?

 

[Harry in Ky]

I think I would start with the key switch. If you can get it out far enough to reach the back side of it with a test light ( I much prefer working with a test light than a voltmeter) terminal 30 should be battery lead. It's powered from a 40A slow blow fuse probably near the starter battery cable stud. Start signal is terminal 50. Terminal 15 and 17 go the glow plug circuit. Terminals AC and BR each lead to the fuse panel and from there to dash, gauges, and other ignition related circuits. That's how the diagram shows it.