2001 Scotts (JD) will only start by jumping at starter

[urdrwho]

My 2001 42 inch - 14 HP Scotts law tractor will not start by key, I must jump the positive terminal of the starter

I tested the solenoid and it tested fine (it is 3 years old)
I jumped the seat safety switch and it wouldn't start
Cleaned the posts of mower safety switch
I haven't checked the safety switch for brake

The engine will start if

1. I place a have the key turned to start
2. Jumper wire from the positive terminal of the battery to the positive terminal of the starter

The engine starts and runs

With other tractors I've owned in the past the darn safety switches are always a PITA. On my WHeel Horse 310 I had some of the switches disabled....oh and yes I did survive.

 

[bertsmobile1]

The seat switch has absolutely nothing to do with any of the starting circuits so leave it alone.
The cranking circuit goes
Solenoid hot terminal > fuse > B terminal on key switch > S terminal on key switch > PTO switch > parking brake switch > trigger terminal on Solenoid.

This is a daisy chain so any single break = no crank
You can back check the sockets for voltage but that requires third hand on the key switch, or jump each switch one at a time till the culprit reveals itself .

Warning

The PTO & BRAKE switches may also have magneto kill wires and connecting them to 12V will fry the control chip in the magneto.
Get a wiring diagram to make sure you don't blow the magneto or pull the blower housing off & disconnect the magneto kill wire.

 

[urdrwho]

Thanks

The weird thing was that for a while the engine would start even if I wasn't sitting on the tractor. Isn't the tractor starting without being on the seat a no-no? Crank would be one thing but full start would be another thing. Right??

I put my meter on the positive terminal on the starter and when turning the key to start, there is not voltage.

I recently put a new belt on and I'm trying to think if I did something.

Three years ago I had this same situation but a new solenoid fixed it.

The seat switch has absolutely nothing to do with any of the starting circuits so leave it alone.
The cranking circuit goes
Solenoid hot terminal > fuse > B terminal on key switch > S terminal on key switch > PTO switch > parking brake switch > trigger terminal on Solenoid.

This is a daisy chain so any single break = no crank
You can back check the sockets for voltage but that requires third hand on the key switch, or jump each switch one at a time till the culprit reveals itself .

Warning

The PTO & BRAKE switches may also have magneto kill wires and connecting them to 12V will fry the control chip in the magneto.
Get a wiring diagram to make sure you don't blow the magneto or pull the blower housing off & disconnect the magneto kill wire.

 

[bertsmobile1]

Seat switch is bypassed by the brake switch so as long as the brake is on & PTO is off you can start the mower with an empty seat
Otherwise it is a tad problematic for techs to service the engine

 

[urdrwho]

Just jump started it and for testing, I engaged the mower PTO without anyone on the seat. Isn't the safety switch supposed to shut down the engine when the seat is empty?

So I shut it down, engaged the PTO, not sitting on seat and jump started it with the PTO engaged --- it started.

Now my thinking is that maybe jumping the starter bypasses the PTO safety switch? But shouldn't the negative side of the switch not allow ignition.

The safety switch for the PTO has four spades. For testing purposes, I'm not sure which female sides of that connector to jumper and bypass the safety switch.

I'm about to do what I did to a Saturn my son once owned. Use a remote starter switch to make things work. On the Saturn it was supposed to be temporary but the switch that needed replaced was in the column and more money than my kid had at that time. The remote starter
fix worked for years.

Seat switch is bypassed by the brake switch so as long as the brake is on & PTO is off you can start the mower with an empty seat
Otherwise it is a tad problematic for techs to service the engine

 

[Smurfy76]

I did a push button start on mine when the ignition switch went out. Alot cheaper and easier to do. Total was 10 buks for the kill switch and the button switch

 

[urdrwho]

Just bought one from Harbor Freight and the gauge wiring isn't good enough. Can't push enough juice.

Wiring may not be able to handle from the battery to the starter. But it can energize from the positive on the battery to the one bolt with the ear, on the solenoid. It will start using such a method. My solenoid has two ears tabs.

So for now I will do the above and be done with it. Does the solenoid jump bypass safety switches?

I did a push button start on mine when the ignition switch went out. Alot cheaper and easier to do. Total was 10 buks for the kill switch and the button switch

 

[Smurfy76]

Yeah I use a car horn button.

 

[bertsmobile1]

Just jump started it and for testing, I engaged the mower PTO without anyone on the seat. Isn't the safety switch supposed to shut down the engine when the seat is empty?

Yes it is so you obviously have some wiring problems that should be sorted out.
The seat switch is there for both your safety & the safety of others in the locality of you mowing


So I shut it down, engaged the PTO, not sitting on seat and jump started it with the PTO engaged --- it started.

If you read & understood my original reply then it would be apparent that jumping directly to the starter motor bypasses the entire cranking circuit so why would it not start ?

Now my thinking is that maybe jumping the starter bypasses the PTO safety switch? But shouldn't the negative side of the switch not allow ignition.
Well yes if you are not using the cranking circuit a safety switch in the cranking circuit is hardly going to have any effect is it ?
There is no battery ignition, the Magneto is self energising so nothing there to stop the engine firing up & blades spinning lopping off a lump of your hand or foot while you are there jumping the starter or you slipping & putting your hand into the belts on the deck, so the belt can not so neatly remove large lumps of flesh.

The safety switch for the PTO has four spades. For testing purposes, I'm not sure which female sides of that connector to jumper and bypass the safety switch.
There is a golden rule about staying alive & well
If you have no idea about what you are doing then DON'T DO IT

I was originally trying to help you diagnose & fix your mower
However you are obviously determined to bastardize the wiring with less than no idea what you are doing & the potential consequences of doing it.
Thus you are now on your own

 

[Smurfy76]

That's a little harsh. You would hate seeing my mower as I bypassed all safety switches with the push button start.