Neutral switch problems

[Laneman950]

Sometimes when I turn the key on my JD950 it just clicks. Problem seems to be in the neutral safety switch. If I move the stick shift around or if I put it in gear and rock the tractor back and forth (gets the gears moving a little) it will start. What's a good way to test the switch? I was thinking next time it fails I could jumper the two terminals on the switch and it should start. Does the switch have any moving parts or adjustments? I can see the switch mounted on the side of the transmission.

 

[john_bud]

Sometimes when I turn the key on my JD950 it just clicks. Problem seems to be in the neutral safety switch. If I move the stick shift around or if I put it in gear and rock the tractor back and forth (gets the gears moving a little) it will start. What's a good way to test the switch? I was thinking next time it fails I could jumper the two terminals on the switch and it should start. Does the switch have any moving parts or adjustments? I can see the switch mounted on the side of the transmission.

Before you tear into that NSS, check the voltage between the block and the starter when you hit the key. You could have a bad electrical connection, bad ground (very common) or internally corroded cable.

The Neutral Saftey Switch's are usually NO or Normally Open. When in the activated position they close or short. Take the meter off the tractor and use the meter to check ohms when the switch is in each position. Should be infinite in the neutral position and near zero in the activated. (opposite if it is NC or Normally Closed).

Then check the wires with the ignition on and off. You should get voltage when it is on. Check the wires for any shorts (common failure mode).

This is just general trouble shooting. There may be more specific's to check, a spin to the JD area may turn that up!

jb

 

[wmgeorge]

Before you tear into that NSS, check the voltage between the block and the starter when you hit the key. You could have a bad electrical connection, bad ground (very common) or internally corroded cable.

The Neutral Saftey Switch's are usually NO or Normally Open. When in the activated position they close or short. Take the meter off the tractor and use the meter to check ohms when the switch is in each position. Should be infinite in the neutral position and near zero in the activated. (opposite if it is NC or Normally Closed).

Then check the wires with the ignition on and off. You should get voltage when it is on. Check the wires for any shorts (common failure mode).

This is just general trouble shooting. There may be more specific's to check, a spin to the JD area may turn that up!

jb

I have an old 650 that is doing the same thing, so pulling the wires off (I'm 120 miles from the tractor!) should let it start if "open" is safe, correct?

 

[jd110]

Pulling the wires off will not let it start. In electrical terms, an "open" circuit is an incomplete circuit. The neutral circuit needs to be "closed" to start. If you are hearing a click when attempting to start, you probably are getting too much voltage drop in the circuit. These tractors did not have a relay in the starter circuit and adding one usually resolves this problem.

 

[wmgeorge]

Pulling the wires off will not let it start. In electrical terms, an "open" circuit is an incomplete circuit. The neutral circuit needs to be "closed" to start. If you are hearing a click when attempting to start, you probably are getting too much voltage drop in the circuit. These tractors did not have a relay in the starter circuit and adding one usually resolves this problem.

NO click and when I "play" around with the gearshift lever it may start with the next key turn. Yes, as a electrician I understand the terms open and closed very clearly but the description I had quoted was somewhat confusing. "Should be infinite in the neutral position and near zero in the activated. (opposite if it is NC or Normally Closed)."

So if the gearshift is not in neutral, the switch is "open", so if I jumper this plug across (short) the next the next time it won't start, and it does... I've got a bad switch. IF I leave it jumped or shorted at the plug connector, will bad things happen to the tractor?

I'm old enough to have driven stick shifts without neutral switches .
THANK You for the reply!! Gee I wish I had a complete wiring diagram (