For those of us facing a refusal to turn over problem, and when the available youtubes video just go over the obvious things, I thought I would share my own experience hoping it could help guys and gals loosing sleep about what could be wrong with their tractor and dreading a trip to the dealer.
Symptoms. Over two weeks, would occasionally not turn over. Panel would light up, but only fuel pump noise. Then died while running.
-> Check battery, ground, fuses. Starter ECU fuse blown. -> replaced. No turn over.
-> After a few more tries with new fuse, that one blew too ->replaced
-> Check other fuses (by the left of the battery) and starter fuse (below alternator) -> OK
-> Check all safety switches -> seat, brake and neutral switches OK. Both PTO switches (under seat) crumbled in my hands on unplugging (this is a described problem). Replaced -> good start!...for about 7 hours. No issues for about half a dozen starts. Then, on the 7th start, won't turn over.
-> got a wiring diagram for the B3350
-> power to starter relay switch OK, on full turn of key in ignition switch but no power to white wire to started solenoid
-> bring 12V to solenoid -> good turn over, normal start
-> check relay (verify continuity after switch click) when 12 V applied across other two poles. -> OK
Thus, problem is in starter ECU on ECU board.
Solutions:
-> cut yellow wire between ECU and relay and ground it (0$ solution; minimal modification)
-> Setup a different feed to solenoid that can be triggered by a push switch (5$ solution if you have wire; you have a new way to start your tractor)
-> Buy a new ECU board ($2700 solution; you forego your next vacation to Florida)
I adopted solution 1 and it works.
Analysis.
At the end of the day, one of the PTO safety switches might have been the original problem. The first fuse I put in was a 10A as a replacement for a 5A. This could have messed up the starter ECU sector of the ECU board causing it to not offer an appropriate ground (through the yellow wire from the ECU). Thus, explaining why bypassing the starter ECU and grounding the yellow wire solved the problem. Of course, this could be a wrong analysis, but tractor is working and spared a trip to the dealer, 2 foot long grass and hundreds of $.
Epilogue. This is of course a zebra, but it describes a systematic way through diagnosis of the problem and the necessity of a wiring diagram once you've gone through the obvious battery/ground/fuses/safety switches. Hoping it helps. Good luck.
Symptoms. Over two weeks, would occasionally not turn over. Panel would light up, but only fuel pump noise. Then died while running.
-> Check battery, ground, fuses. Starter ECU fuse blown. -> replaced. No turn over.
-> After a few more tries with new fuse, that one blew too ->replaced
-> Check other fuses (by the left of the battery) and starter fuse (below alternator) -> OK
-> Check all safety switches -> seat, brake and neutral switches OK. Both PTO switches (under seat) crumbled in my hands on unplugging (this is a described problem). Replaced -> good start!...for about 7 hours. No issues for about half a dozen starts. Then, on the 7th start, won't turn over.
-> got a wiring diagram for the B3350
-> power to starter relay switch OK, on full turn of key in ignition switch but no power to white wire to started solenoid
-> bring 12V to solenoid -> good turn over, normal start
-> check relay (verify continuity after switch click) when 12 V applied across other two poles. -> OK
Thus, problem is in starter ECU on ECU board.
Solutions:
-> cut yellow wire between ECU and relay and ground it (0$ solution; minimal modification)
-> Setup a different feed to solenoid that can be triggered by a push switch (5$ solution if you have wire; you have a new way to start your tractor)
-> Buy a new ECU board ($2700 solution; you forego your next vacation to Florida)
I adopted solution 1 and it works.
Analysis.
At the end of the day, one of the PTO safety switches might have been the original problem. The first fuse I put in was a 10A as a replacement for a 5A. This could have messed up the starter ECU sector of the ECU board causing it to not offer an appropriate ground (through the yellow wire from the ECU). Thus, explaining why bypassing the starter ECU and grounding the yellow wire solved the problem. Of course, this could be a wrong analysis, but tractor is working and spared a trip to the dealer, 2 foot long grass and hundreds of $.
Epilogue. This is of course a zebra, but it describes a systematic way through diagnosis of the problem and the necessity of a wiring diagram once you've gone through the obvious battery/ground/fuses/safety switches. Hoping it helps. Good luck.
