Gwydyr
New member
My 1992 Ford 2120 has been great but I've been struggling to figure this issue out for over a year now. I致e been putting off posting about this until I had as much information collected as possible so here it goes.
The tractor will periodically get into the habit of randomly dropping out of gear. Sometimes I can just shift into nuetral and back into gear and continue, sometimes it will happen repeatedly every few feet until it won't move at all. This was the case last summer, but through the winter it worked fine, and now I haven't got it to move in weeks. I see a lot of threads on different forums about issues relating to the HSS systems and there are basically two kinds of problems: failed/worn HSS clutch packs, or electrical problems relating to the computer under the dash. Many people replace electrical parts only to find out that their clutches need replacement which costs about $1500.
However unlike anyone else, when the tractor randomly stops and won't shift out of neutral, if I shut it off it will not restart. Usually, if I jiggle the yellow neutral start switch (part 23 in the first diagram) that leads to the starter solenoid it will start up again and will usually shift into gear. However, now turning the key causes the dash lights to dim, but it will not turn over. If I attach wires across where the neutral start switch plugs in, I can bypass it and it starts, but still will not shift. I have replaced both this switch (23) and the short section of wiring harness the leads to it (23a) and that I can jump across.
In order to try and diagnose whether the pump or relief valve was to blame, I rigged up a hydraulic pressure tester that splices into the lines between the pump and valve that send pressure to the HSS clutch when the solenoid opens the valve. The pressure is at spec, over 200 psi, but does not change when I shift. Does this mean that my solenoids are not engaging, and therefore the problem is electrical? I doubt the solenoids are the issue because it is unlikely that both would go out simultaneously.
This year my trouble began after pressure washing, which can wreck the "electronic control assembly", which is a plastic box that has a label that states "do not remove this label" (part 31 in the second diagram). Remanufactured units cost $400, and before replacing this, I want to be sure it is the problem. Is there any procedure for testing it? I have already replaced part 24 in the second diagram, which reads the position of the shifter and sends the signal to the control box, and then to the solenoids which engage the hydraulic valves. The only other option I can think of is that there is something wrong with the wiring harness itself because I think dimming dash lights but not turning over indicates that there is resistance somewhere.
My shop manual only covers the earlier models with the mechanical linkage to the solenoids, so there isn't much in terms of electrical tests I can do right now. Does anyone have access to the post-1992 manual? Thanks
The tractor will periodically get into the habit of randomly dropping out of gear. Sometimes I can just shift into nuetral and back into gear and continue, sometimes it will happen repeatedly every few feet until it won't move at all. This was the case last summer, but through the winter it worked fine, and now I haven't got it to move in weeks. I see a lot of threads on different forums about issues relating to the HSS systems and there are basically two kinds of problems: failed/worn HSS clutch packs, or electrical problems relating to the computer under the dash. Many people replace electrical parts only to find out that their clutches need replacement which costs about $1500.
However unlike anyone else, when the tractor randomly stops and won't shift out of neutral, if I shut it off it will not restart. Usually, if I jiggle the yellow neutral start switch (part 23 in the first diagram) that leads to the starter solenoid it will start up again and will usually shift into gear. However, now turning the key causes the dash lights to dim, but it will not turn over. If I attach wires across where the neutral start switch plugs in, I can bypass it and it starts, but still will not shift. I have replaced both this switch (23) and the short section of wiring harness the leads to it (23a) and that I can jump across.
In order to try and diagnose whether the pump or relief valve was to blame, I rigged up a hydraulic pressure tester that splices into the lines between the pump and valve that send pressure to the HSS clutch when the solenoid opens the valve. The pressure is at spec, over 200 psi, but does not change when I shift. Does this mean that my solenoids are not engaging, and therefore the problem is electrical? I doubt the solenoids are the issue because it is unlikely that both would go out simultaneously.
This year my trouble began after pressure washing, which can wreck the "electronic control assembly", which is a plastic box that has a label that states "do not remove this label" (part 31 in the second diagram). Remanufactured units cost $400, and before replacing this, I want to be sure it is the problem. Is there any procedure for testing it? I have already replaced part 24 in the second diagram, which reads the position of the shifter and sends the signal to the control box, and then to the solenoids which engage the hydraulic valves. The only other option I can think of is that there is something wrong with the wiring harness itself because I think dimming dash lights but not turning over indicates that there is resistance somewhere.
My shop manual only covers the earlier models with the mechanical linkage to the solenoids, so there isn't much in terms of electrical tests I can do right now. Does anyone have access to the post-1992 manual? Thanks
