New Holland Boomer 1020 Won't Crank - Hydrostatic Transmission Safety?

[mazog755]

My boomer 1020 periodically will not crank - apparently due to a hydrostatic transmission safety feature. I turn the key to warm the plug, then turn to the start position - nothing happens. While holding the key in the start position, I wiggle the shifter in the neutral position and it cranks, starts, and runs fine.

After my last mow, I stopped in the driveway to clean off the mower deck. I then could not get that machine to crank. I ended up putting it on dollies to put it away. Three days later I turned the key and it started right up.

Based on what I have seen, I suspect that there is a safety that is not recognizing that the transmission is in neutral. However, after my last experience, I started thinking that maybe the transmission is getting hot, and something is sensing an overheat condition. I've been dealing with this issue for a while - if I have to deal with a stuck "no-start" tractor one more time I'm going to blow this thing up.

I cannot see any physical safety switch connected to the Low-Neutral-High shift lever, so I'm thinking that the safety sensor is inside the transmission. There is an electrical plug with two leads on the left side of the rear of the machine, but I cannot tell if it is "field replaceable". In the past I have replaced the controller and the entire wiring harness (stupid mice!) on this machine. I'd be shocked if a second controller went bad.

I don't know how to troubleshoot this problem. Any ideas are appreciated!

Jim M.

 

[WranglerX]

A wiring diagram would help.... Maybe get shop manual....
Maybe try to bypass "suspected" neutral safety switch (two wires out of transmission) and see if it solves problem...

 

[dlctcg]

Maybe try to bypass "suspected" neutral safety switch (two wires out of transmission) and see if it solves problem...

^^^ This would be the first thing I would try... If it resolves the issue the switch is good & you have a wiring issue or the linkage may need to be cleaned & adjusted. If the issue is still happening, I would get the test procedure for the switch & test it, both when the machine is cold / cool & after running it at normal temp.