310-8 won't shut off

[waffle 29]

This is the 10hp Magnum engine..... Turn key off and it continues to run. Replaced the key switch and same issue. All wiring appears fine....... So i actually ran a wire from the battery straight to the ignition module to make sure it was definitely grounded and with key switch off which should kill the engine but still won't shut off. I'm baffled that grounding the module won't kill the engine. Any thoughts on what I'm not understanding?....... Jim

[953 nut 56,214]

Wiring on 310-8s has had some changes over the years, give us the model number from the tag under your seat to be sure.

The first suggestion would be to make sure the ground wire to the terminal on the side of your ignition switch is going to a good ground on the frame.

[Achto 27,940]

14 hours ago, waffle said:

All wiring appears fine....... So i actually ran a wire from the battery straight to the ignition module to make sure it was definitely grounded and with key switch off which should kill the engine but still won't shut off. I'm baffled that grounding the module won't kill the engine.

 

Your ignition coil should look like this.

 

The kill wire from your switch should be connected to the terminal at the top center of the coil. Ground this terminal out to kill the engine. I would remove the fan shroud and check to make sure that the kill wire is for sure connecting to this term.

Edited January 8 by Achto

[waffle 29]

I checked the tractor number and it's #2110K806    37974.......... My father bought this one new so it's a keeper. Not sure exactly when Toro started putting their name in the decal but this one still only has Wheel Horse. I actually bought a 310-8 new myself in July 1986 and it has points..... And for a very good laugh for you guys, I had zero money and needed a mower to use on the house I just had bought so took out a personal loan for it. Tractor was $3176 which included a new 42"deck and interest rate was 14.75%.Still have the paperwork..Amazing thinking about it now and it's also a keeper and going strong..............

 

And yes, the wires are fine at the module and I even have installed a new ignition module as the plug wire was frayed terrible and would not shut off with either module.. All I check and double check is grounded fine.......... Jim

[gwest_ca-(File Mod) 11,146]

Some engines have an optional diode in the ignition wire.  I can only guess it is on the engine side of the engine/tractor connector. Will feel like a small lump under some electrical tape. Some models also have a diode in the other wire to rectify the charging current so don't get them mixed up.

If the diode has failed in an open state grounding the ignition wire after the diode will not kill the ignition. 

[WHX?? 49,515]

Kill wire open in the shroud or at the mag. But it sounds like you covered that. 

1 hour ago, gwest_ca said:

an optional diode in the ignition wire.  I can only guess it is on the engine side

Wonder what the purpose of the diode is? 

[gwest_ca-(File Mod) 11,146]

The diode blocks any stray voltage from getting to the module.

Since it is part of the Kohler wiring harness it only shows up in the Kohler wiring diagrams.

 

[953 nut 56,214]

There is a five pin connector near the engine (only has four wires). The dark blue wire is the KILL wire for your ignition system.

Pull that plug and use an ohm meter to see if the Dark Blue wire from the tractor side has continuity to ground with the ignition switch in the OFF position. That will check out which side of that plug the problem is on.

This wiring diagram set should also be helpful.

 

 

Edited January 8 by 953 nut
fat finger

[waffle 29]

I cant get to any of it today, but will dig in Thursday morning. Already did so many wiring checks I'm cross eyed anyways. Im still very frustrated figuring out that no matter what position the key switch is in, when I use a jumper wire straight from the battery negative post or frame right to the module itself bypassing all wires and connections, tractor won't shut off. Wont kill it?....... Jim

[953 nut 56,214]

23 hours ago, waffle said:

installed a new ignition module

 

6 hours ago, waffle said:

when I use a jumper wire straight from the battery negative post or frame right to the module itself bypassing all wires and connections, tractor won't shut off.

When you installed the new magneto coil did you clean the point where the new coil is mounted to be sire it is well grounded? Your kill wire needs a complete path to ground on the primary side to stop the secondary from developing voltage. 

[waffle 29]

Well.... Mystery solved! After doing all the obvious troubleshooting and triple checking and all proved just fine, I swapped out the brand new ignition module with another old one off a 312 I have and it shuts off as it should. I replaced the module I had because the insulation was mostly gone off the secondary wire to the plug. Bought one off Ebay so guess it's just another example of junk china replacement parts and seeing as its an electrical part, they wont refund my money..... Anybody know if there is a good new replacement out there? Maybe I should just buy a used one If I can find one and be better off!..... Jim

[OutdoorEnvy 1,634]

Glad you got it figured out.  Electrical issues can be about the most annoying thing to diagnose and especially with the mixture of parts and other unknowns from previous ownership.

[waffle 29]

 Guess I forgot what I already have learned previously..... Just because a part is new, you can't assume its good especially these days....... Jim

[WHX?? 49,515]

Absolutely Waffles ... off shore carbs and fuel pumps come to mind.