M120 Powershift Neutral Light

RobertsW

New member

Equipment
M120
Oct 1, 2022
1
0
1
Minnesota
Hello,

I have recently purchased an M120 powershift. I don't know any of the prior history. The hour meter is at 2,450 and appears to be original. The tractor has been finicky on shifting since purchased. The first caution that was thrown was (c) with the 3 beeps once the clutch was released. Once the tractor idled for around 20 minutes the issue seemed to resolve itself. I put 20hrs on issue free running a corn chopper. Now however the neutral light won't turn on. Meaning no shifting is able to take place and the gear indicator doesn't give any reading. I have traced all wires. Checked Ohms. Voltage is appropriate for all the tests per the manual. I had the voltage regulator/alternator tested and new components put in. When the key is cycled occasionally the neutral light will randomly come on and tractor will perform appropriately. The issue seems to be temperature dependent. If I slowly warm the powershift control unit the neutral light will start to flicker and then come on. Sometimes it doesn't and then if I come back 20 minutes later it will for one cycle of the ignition.

I have around 30hrs of trouble shooting into it. Has anyone heard of the powershift control unit failing? Does anyone have test units for verifying a malfunction? Part number is 3F250-78502. Tractor serial 50269.

When transmission neutral light is on I am able to go through all function pages and all checks pass per the manual.

Any help or thoughts would be greatly appreciated. I just want to make sure I'm not missing something simple before ordering a $1200 computer. Thank you in advance.
 

William Chisholm

New member

Equipment
Kx121-3,M120,Bobcat 743
Aug 1, 2021
10
0
1
ALABAMA
Hello,

I have recently purchased an M120 powershift. I don't know any of the prior history. The hour meter is at 2,450 and appears to be original. The tractor has been finicky on shifting since purchased. The first caution that was thrown was (c) with the 3 beeps once the clutch was released. Once the tractor idled for around 20 minutes the issue seemed to resolve itself. I put 20hrs on issue free running a corn chopper. Now however the neutral light won't turn on. Meaning no shifting is able to take place and the gear indicator doesn't give any reading. I have traced all wires. Checked Ohms. Voltage is appropriate for all the tests per the manual. I had the voltage regulator/alternator tested and new components put in. When the key is cycled occasionally the neutral light will randomly come on and tractor will perform appropriately. The issue seems to be temperature dependent. If I slowly warm the powershift control unit the neutral light will start to flicker and then come on. Sometimes it doesn't and then if I come back 20 minutes later it will for one cycle of the ignition.

I have around 30hrs of trouble shooting into it. Has anyone heard of the powershift control unit failing? Does anyone have test units for verifying a malfunction? Part number is 3F250-78502. Tractor serial 50269.

When transmission neutral light is on I am able to go through all function pages and all checks pass per the manual.

Any help or thoughts would be greatly appreciated. I just want to make sure I'm not missing something simple before ordering a $1200 computer. Thank you in advance.
Sounds like something close to what I have. Been working on this for 4 days and had the dealer service truck out and damn if it didn't move after he jumped the safety switch. Shut it down, ate lunch and had wild dreams about what I was going to get done, went back down, cranked her up and.......SOS. Aimelessy fooled around and detected what I thought was an indication of a faulty (intermittant) starter switch, ordered that and put it in and....SOS. So...I'm stuck in the middle of the field with a dead "mule". Made some measurements on the Power shift switches and nothing made sense, (I have a WSM) so I'm shy in ordering the parts. No confidence. Intuition tells me it's not a computer problem. I am leaning more towards a hydraulic valve which I will persue in the morning. PLEASE stay in touch.
Bill Chisholm

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