Ford 2120 HSS again.

[DaveBN]

Posted previously on 7/14/23 but have more info now. I'm trying to help a friend with his tractor that stops forward travel when first in use. It will go forward maybe 50 feet or less the stop moving. After 10 seconds it starts moving again. While it's not moving the loader and 3 point hitch work normally. It will start and stop every few seconds then eventually work ok. Reverse seems ok. It does this in all gears and all transmission ranges. I've replaced all fluids and filters with no improvement. My friend took the tractor to an old Ford mechanic who said he could fix it. The mechanic says the control module is bad but could not locate a replacement part. That part is number SBA 385080900R. Does anyone know of a source for this part? I am an electronics tech and am tempted to open this part up to try to repair it. Has anyone done this? Is their a schematic for this part?
One odd thing is the tractor seems to work ok in cold weather like when plowing snow. It also seems to work ok after it warms up as in running for 30 minutes or so. This really puzzles me as it should work either cold or hot but not both.
No, I don't know what tests the other mechanic performed but I'm told it was very extensive and eliminated all items but the control module.
Dave

 

[Bern]

Posted previously on 7/14/23 but have more info now. I'm trying to help a friend with his tractor that stops forward travel when first in use. It will go forward maybe 50 feet or less the stop moving. After 10 seconds it starts moving again. While it's not moving the loader and 3 point hitch work normally. It will start and stop every few seconds then eventually work ok. Reverse seems ok. It does this in all gears and all transmission ranges. I've replaced all fluids and filters with no improvement. My friend took the tractor to an old Ford mechanic who said he could fix it. The mechanic says the control module is bad but could not locate a replacement part. That part is number SBA 385080900R. Does anyone know of a source for this part? I am an electronics tech and am tempted to open this part up to try to repair it. Has anyone done this? Is their a schematic for this part?
One odd thing is the tractor seems to work ok in cold weather like when plowing snow. It also seems to work ok after it warms up as in running for 30 minutes or so. This really puzzles me as it should work either cold or hot but not both.
No, I don't know what tests the other mechanic performed but I'm told it was very extensive and eliminated all items but the control module.
Dave

I am generally hesitant to blame a control module until I have exhausted all other possibilities. Assuming the forward and reverse solenoids are the same (and I'm just assuming here, I don't know this to be a fact), could you swap the wiring between the two as a test and see what happens? If you do that and the problem goes to reverse and forward is OK, then you know it's a control module or a shift lever issue. If the problem stays with forward, then you know it's a solenoid and/or control valve problem.

 

[DaveBN]

Thank you Bern, I'll try that.