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TonyToro

GT-1100 ignition switch help

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I searched the site but didn't find the info I need.  I am working on this tractor for my father inlaw to pull with. I took all the implements and safety switches off. I just got this new replacement switch for switch model #103991. Now that I eliminated a bunch of wires and possibly now the wires are not in the correct spot for the switch, the tractor doesn't start. This tractor has a starter solenoid and volt meter as well. Can someone please tell me which wire needs to go to which pole on the switch.

 

thank you

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Not knowing what tractor you have one can only guess.  103991 switch is for mag. run engines so there will be a post marked M, mag. I (ignition)  to coil on battery run models.  R to rectifier. B is power to switch, from battery or battery side of solenoid. S to the starter post on the solenoid. A (accessory) to light switch or hour meter. G I think was not used on the one I went through this summer. It had the wrong switch in it when it came in and it put power into ign. system and destroyed the ign. module, so it had to be replaced too.

 

Go through the schematics to confirm but my C141's  w/103990 switch run very well and are much less frustrating without MR. OSHA's nose trying to gum up the works. However, MR. OSHA does have some good points too.

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Thanks guys for the replies.  I looked at the schematics and noticed "red" on the top  leading from the magnito/spark plug. Any idea what that is? Also my tractor didn't have a rectifier. Is it supposed to have one? 

I would have included model number and serial number by that tag is completely sun faded. 

 

So what I connected to that ignition switch is:

coil wire to the S post

magnito to M

volt meter to B ( fuse from solenoid to volt meter out to ign. Switch)

ground to G

 

This tractor was a wiring mess plus had an electrical melt down. 

 

Oh oh another thing I found was a small diode of some sort coming off one of the wires along the frame from the magnito. 

 

 

Thanks again for the input.

10 minutes ago, wallfish said:

switch.jpeg.f33684b6199bf25a5035dd9f6bde12b4.jpeg

Oh that makes it very clear. Thanks.

I don't have a regulator....not that I have found anyway.

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In the schematic the red wire at the engine shows the diode symbol. That is your rectified but unregulated charging circuit to charge the battery. Then it turns to white and goes to the R terminal on the ignition switch.

To be safe you can leave the magneto ignition wire off the switch and safely away from any battery voltage until you get it running. One slip and the magneto will go up in smoke. To shut the engine off ground the ignition wire to the chassis or hook it back up to the M terminal.

 

Do you have an ammeter or a voltmeter?

If ammeter the power to the ignition switch is OK.

If it is a voltmeter they need to be wired so they are not powered in the key OFF position. You could use the A accessories terminal to power it and the other terminal just needs to be grounded.

 

Garry

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1 hour ago, gwest_ca said:

In the schematic the red wire at the engine shows the diode symbol. That is your rectified but unregulated charging circuit to charge the battery. Then it turns to white and goes to the R terminal on the ignition switch.

To be safe you can leave the magneto ignition wire off the switch and safely away from any battery voltage until you get it running. One slip and the magneto will go up in smoke. To shut the engine off ground the ignition wire to the chassis or hook it back up to the M terminal.

 

Do you have an ammeter or a voltmeter?

If ammeter the power to the ignition switch is OK.

If it is a voltmeter they need to be wired so they are not powered in the key OFF position. You could use the A accessories terminal to power it and the other terminal just needs to be grounded.

 

Garry

Ok thanks. I wil give is a try tomorrow evening. Hopefully it runs.

 

oh 2 more questions with the wiring. One wire goes to the bottom of the throttle plate from the magnito. What does that do? Just a ground?

Also this engine doesn't have a ground wire to the chassis. Should it be?

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8 hours ago, TonyToro said:

oh 2 more questions with the wiring. One wire goes to the bottom of the throttle plate from the magnito. What does that do? Just a ground?

 

Will guess you are referring to the control panel below the carb. B&S included a grounding switch in the panel so when the throttle in is the extreme idle position it will shut the ignition off. I have removed the wire from the spring clip and capped it so it does not cause grief later if it also has an ignition switch.

 

Quote

Also this engine doesn't have a ground wire to the chassis. Should it be?

They are relying on the metal to metal contact between the engine and the frame to provide a ground. I try to move the negative battery cable to one of the engine mounting bolts because the electric starter is the largest single load it will ever see. Then add another smaller ground wire from the engine to the chassis to ground the other loads. As these tractors age the metal to metal contacts oxidize and their ability to provide a good ground diminishes. You don't have much going on electrically so should be good as is.

 

Garry

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On 10/10/2017 at 5:59 AM, gwest_ca said:

 

Will guess you are referring to the control panel below the carb. B&S included a grounding switch in the panel so when the throttle in is the extreme idle position it will shut the ignition off. I have removed the wire from the spring clip and capped it so it does not cause grief later if it also has an ignition switch.

 

They are relying on the metal to metal contact between the engine and the frame to provide a ground. I try to move the negative battery cable to one of the engine mounting bolts because the electric starter is the largest single load it will ever see. Then add another smaller ground wire from the engine to the chassis to ground the other loads. As these tractors age the metal to metal contacts oxidize and their ability to provide a good ground diminishes. You don't have much going on electrically so should be good as is.

 

Garry

I unbolted the engine cleaned one spot and put a ground to the chassis. Thanks for the tip. 

But now I have another problem. That diode broke. It must have been brittle in the electrical meltdown. Does anyone know what it is and where I can get one?

 

The engine turns over so that's a plus. lol

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You have a 3 amp charging system so a 6 amp diode is a suitable replacement. Do you still have Radio Shack or another local electronics supplier?

Wired stator to diode ->I- diode to ignition switch

 

Garry

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24 minutes ago, gwest_ca said:

You have a 3 amp charging system so a 6 amp diode is a suitable replacement. Do you still have Radio Shack or another local electronics supplier?

Wired stator to diode ->I- diode to ignition switch

 

Garry

Ok perfect. Thank you!!

Yes I have an electronic shop close by. I'll swing in there tomorrow. 

This tractor is fighting every step of the way! 

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The electronic shop had exactly what I needed. 

I have everything I can wire wired but the diagram shows a third wire coming off the stator? I took the flywheel off again and took the stator off. I don't see any broken wires. The diagram is saying I need 

S start

b battery

r regulator

m magnito

g ground

a accessory 

 

I have all but that magnito. Is it needed?

 

 

IMG_2710.JPG

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Where was the ignition coil or magneto? Should be one wire going to it and that is what shuts it off when grounded by the ignition switch.

 

I can't tell from the engine parts list if your engine used a set of points and condenser or an electronic module in the ignition coil. 

 

Garry

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12 minutes ago, gwest_ca said:

Where was the ignition coil or magneto? Should be one wire going to it and that is what shuts it off when grounded by the ignition switch.

 

I can't tell from the engine parts list if your engine used a set of points and condenser or an electronic module in the ignition coil. 

 

Garry

The coil is mounted right above the flywheel? I'm not sure what this tractor is supposed to have. It had an electrical meltdown before I got it and the guy wasn't to handy...... being nice here. Lol

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This is the engine parts list I was looking at. Click on the picture to see what spec numbers were used for each model.

If it has points they should be under a cover on the front right side of the block down low. (Lower than the carb and on the opposite side)

The wire that goes from the points to the coil is the one the magneto wire to the ignition switch connects to.

If no points the ignition wire goes to the electronic module clipped to the ignition coil. Forget what that area looks like - been a while since I converted one.

 

This may be what the coil with module looks like showing the ignition wire.

 

Garry

B&S Ignition ground wire on coil.jpg

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This is a module that was available to convert point ignition to electronic. It may have been the same as used in the early magnetron coils from B&S.

Hard to read so here is a link to a pdf version

 

Garry

 

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