Riding mower ignition problem.

Stephen Newell

Well-known Member
I have a Ford LGT 100 riding mower. When I turn the ignition key to the first position there is power at the coil. Then when I turn it to the start position there is no power at the coil. Briefly while the engine is still turning and I release the key to the first position the spark plug fires so I know the coil and points are good. I thought there was a problem with the ignition switch so I bought a new one and the new one does the same thing. What should I be looking for?
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For some reason, the terminal on the switch marked "A" (Accessory) is connected to the ignition system, rather that the one marked "I" (Ignition).

Either wires have been switched in the connector at the switch, or the incorrect generic switches are being used/tried. (There are quite a few configurations of those lawn tractor ignition switches, all of which look the same but terminal locations and internal switching patterns differ.)
Engine manual .pdf
 
Bob is correct. There are several with the same black plug but the switch is internally different. You need the "I think this is right,,"' an "I" type terminal not a "M" terminal. Your power is a "B" terminal. Starter is "S". Anything to play with your head. Sounds like your switch internally wore out.
 
The original switch was rusted solid. I've been trying to get the mower running with two new switches. For some reason Bob's link isn't working for me. I will see if I can get more info on which wire goes where.
 
Ok, this is what I have. The heavy tan from the B on the start switch goes to the starter solenoid. The white wire from the S on the start switch goes to the starter solenoid. From L on the start switch there is two outgoing wires. The purple wire goes to the + on the coil. The red wire which is changed to orange goes to this unknown device then has two white wires that go to the engine.
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From what you describe, you have an ignition switch for magneto ignition,
What you need is a switch for battery ignition.
 
the unidentified device is the voltage regulator. That tractor had a stator under the flywheel and magnets on the flywheel to make it work. The two small white wires go to the stator.

While there are different types of switches for garden tractor they fall into two categories. Battery ignition and Magnito ignition. They will use the same plug on many but on the battery one when turned on it provides power to the coil. A Magnito system the mag produces it's own power and doesn't draw off the the battery. When the key is turned to the off position it grounds the system out.

Any auto parts place should have an outdoor power equipment book and should be able to get you the correct switch for it.

Rick
 

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