Tractor will not turn off at key switch!

[Little Rosebud 8N]

My 8N would not run for some time. Mostly electrical problems. It was changed to 12V system before I purchased Little Rosebud. (This name was given to her by my wife.) I have done quite a bit of work on her and she runs great. So good in fact that she will not turn off with the key switch. I replaced the key switch, checked the terminal block for run around power, checked condition of wiring, traced all wiring from a conversion wiring diagram and everything checks out good. The only way I can shut her down is to turn the gas off and wait for her to die or by removing the primary coil wire (at the terminal block). I thought about putting an in-line toggle switch on the primary coil wire. This would kill the power to the coil when the toggle was flipped to the off position. Would this be advisable? I have worked on a lot of older cars but new to tractors. Thought I knew most of the problems that could occur but this is new to me.
I am at my wits end..any suggestions would be much appreciated!

 

[old]

Sounds like a back feeding alternator and you need to cut the wire going to the #1 terminal in your wiring and install a light bulb or resister or diode in that wire and it will then shut off like it should. I use Radio shack part #276-1661 silver line on that diode goes to the alternator side of the wire

 

[gutterman]

(reply to post at 19:59:56 09/23/10)

listen to old, mine had to be choked to death to shut down, until i put in a lite. sounds odd but it works, i tryed useing a GOOD pair if insulated plyers to pull off the coil wire.....3 miles away i was heard. yelling like rambo when they put the jumper cables to him......sparkes came out the toe of my shoe into the frount rim,,,i saw them.. as my heart jumped in my chest...my big toe was numb for 30 min. after..sure its funny now

 

[souNdguy]

yep, 194 lamp or a diode as old suggests.. very likely the issue you are having is alt backfeeding the ignition due to no isolation..

soundguy

 

[Devious]

I was told by someone that if the Diode is installed the wrong direction, that it will do the same thing. Maybe I misunderstood something tho. Devious

 

[old]

If the diode was in back wards the alternator should not charge the battery because it does not get power to the excite circuit of the alternator

 

[Little Rosebud 8N]

Wow..you guys are great! Thanks for the info. I looked back on my wiring diagram and there it was just like you said. A 5 watt light bulb or a diode in the line. I saw that but it did not ring a bell with me.
OLD...thanks for the info and part number from Radio Shack.
Gutterman...my wife and I laughed till we hurt over your shocking experience.
Thanks for all the post and I will certainly be back on this forum for info and laughs!