1720 No Start/Neutral Start Switch

[Ravenz10]

After several years of a troublesome Neutral Start Switch, it finally gave out a month or so ago. Since then, I used a small jumper on the two nodes at the top of it to get the tractor running, which worked well for some time. I generally jumpered it only temporarily to get the tractor started, but it became a pain and just left the jumper in place at all times, unless it became disconnected thru movement of the shift lever. Well, it got to a a point where the tractor would not start at all, with or without the jumper. I disconnected the switch's connector from the wiring harness, and applied another jumper to the harness side of the leads, without success. All that is produced is the solenoid clicking. Battery is fully charged with good connections, and the fusible link has been replaced.

I am thinking that perhaps the constant open from the Neutral Switch may have damaged some solenoid circuitry? I am planning to get the starter/solenoid bench tested Monday. When I short the hot terminals on the solenoid, it does actuate the starter, and turns the engine, but not long enough to actually get the tractor running.

The other idiosyncrasy with this tractor that I have lived with for years is that to turn it off, it is necessary to turn the headlights on, while the key is off. Headlights and flashers work fine while running.

More to come.

 

[Morning Wood]

I had a starting issue with my 1720. It turned out to be a bad ground. There isn’t much going on electrically in these things. Keep everything greased up and chase all the wiring down and make sure it isn’t damaged and corroded and things should work. My father had bypassed the neutral safety switch on it as well when it stopped working. It was a hazard though because you could start the tractor while in gear. I think that switch is susceptible to water because of where it sits.

 

[kirkawilson]

View attachment 1920 wiring diagram.pdf Your shut-down problem sounds like a problem with your fuel solenoid wiring. Your starting problems are very common with these ##20 series tractors. After many failed troubleshooting attempts, I bypassed my entire 1920 wiring harness and installed a push-button starter on the dash that shunts from the starter post to the solenoid. All safety switches are also bypassed so I am extra careful before starting.