[Just some guy]

Hello all, I am having some ignition switch issues and need a little help. The old switch would work to start tractor but would not shut it off, weird I thought, so I bought a new one and it is doing the same thing, the switch is a #365402, a 5 male prong type for an older Craftsman 2 tractor. Can anyone tell me if I got a new switch that is bad also or tell me a possible way to test switch to see if it is indeed bad,or could there be another possible problem? I did check the ground wire coming off of pigtail connector that goes to side of frame and it is good and tight. Don't know much about tractors so I figure I would ask before spending any more cash. Any info will be appreciated, Thank you.

 

[engine2quarters]

Welcome to MTF, Just Some Guy.
As an owner of a Craftsman II, that the previous owner put the incorrect switch in and kept blowing fuses, then sold it to me..make sure you have the correct switch. The switch may look like it's correct from its physical shape, but the internals could be much different from what is needed.
I looked on www.sears.com using my machine's model number (917.257621), found the correct part number (140399), then went to the local NAPA store, who could have one in my hands the next morning. Their 'small engine' book even had the contact diagram so I could verify it that way, too. Just make sure keys come with it (some times keys are extra).
In the owner's manual, on the electrical diagram, there might be a diagram showing which contacts in the switch are closed at what position the switch is in. Use a volt-ohm/continuity meter to prove that out.
What's you machine model number?

 

[mmccarty]

I'm not familiar with your specific tractor, but most kill switches work by grounding the ignition. There should be a wire coming back from the motor to the switch. This wire is switched to ground when the key is turned to OFF.

Check out this diagram, the Magneto terminal is switched to Ground to kill the engine:

http://sears.pammar.net/switch.pdf

Find the kill wire coming back from the motor. Ground it to see if it actually kills the engine, if not it is disconnected at the motor. If it does kill the motor, you either have a bad ground or a bad switch. You can check the switch with an ohmmeter. In the OFF position the Magneto terminal should read continuity to ground. In the run position it will read open.

 

[Jon318]

In the OFF position the Magneto terminal should read continuity to ground. In the run position it will read open.

And what if you have to jiggle the key in the off position or hold it to the left to ground it out?

 

[mmccarty]

And what if you have to jiggle the key in the off position or hold it to the left to ground it out?

Then I'd imagine that you either have a worn out switch, a loose connection on the back of the switch, or a loose ground that is making and breaking when you jiggle things.

 

[Jon318]

Thinking just a worn out switch, do you think it would have an effect on the charging system on say...an older suburban with a voltage regulator? I personally dont think so cause the regulator controls charging...but hey, doesnt hurt to ask right?

 

[mmccarty]

Thinking just a worn out switch, do you think it would have an effect on the charging system on say...an older suburban with a voltage regulator?

Take a look at this diagram:

http://sears.pammar.net/h.jpg

All connections to the battery come through the switch. Are you having intermittent charging problems? Your ammeter should show whether you are charging or not. (I assume most Suburban models have an ammeter).

 

[Jon318]

Thanks. It started charging than burned up the ammeter wire. Re-wire soon to be in progress.


To the OP, sorry for the hijack. Ive had the same problem on another machine. Needed to get the exact one for it or else it kept popping fuses.

 

[mmccarty]

Thanks. It started charging than burned up the ammeter wire. Re-wire soon to be in progress.

I assume the ammeter swung heavily to the discharge side before things started smoking? You have something shorted out someplace. Since there are no fuses the ammeter wire became your fuse.

 

[Jon318]

Actually it swung halfway up the charge side before it started smoking... weird huh?

 

[mmccarty]

Actually it swung halfway up the charge side before it started smoking... weird huh?

That's strange. I assume the battery was good and that you didn't start it by other means and try to make it charge a bad battery?

 

[mmccarty]

I'm trying to think of other causes...

A miswired or faulty switch could ground the accessory lead and cause excessive charging current in that direction.

A failed voltage regulator could have caused high system voltage causing excessive current to the battery. Stuck contacts in the regulator or a bad regulator ground will send the voltage to 16 volts or more.

 

[Dude11]

As others have mentioned,switches Are different-some normally open,some normally close.you will need a volt/ohm meter to tell,that's the only way to know for sure how or which you have.Beats the ole,jump off run around and jerk the plug wire approach.:biglaugh:

 

[migraineman]

Make sure you have a good ground from the switch body all the way to the engine block. A good multimeter is a sound investment if you don't already have one. Often, the switch body is grounded through the mounting nut on the dash panel. Otherwise, there should be a ground wire connecting the switch to the metal chassis.

Ah, I miss the good ol' days, where a real man would hop off his tractor (which would continue to run ...) and press the ground tab onto the spark plug to stop his engine. He would do this without spilling the bourbon in his highball, and without disturbing the glowing ember in his pipe.

 

[engine2quarters]

Speaking of the spark plug grounding 'finger'.....the previous owner of my Gilson added the 'finger' because the switch contact burned up that would short the mag. Best of two worlds.

Bet O.S.H.A. would disapprove of the shorting 'finger' nowadays.

 

[Just some guy]

Thank you to all, will try these ideas out over the weekend and see what happens, borrowed a digital multi-tester and armed with my recently acquired wiring drawing I will do some tests and see what else I come up with,will let you know what happens ::...Model number is 917.255813http://www.mytractorforum.com/images/smilies/thanku.gif