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1.big.l

Im working on a 312-8 mower need key switch help

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Posted (edited)

Hi everyone got another wheel horse im working on.. this time its a friends 312-8

 

im trying to figure out why the key wont turn the engine off... i hooked up the magneto ground to the switch like ive seen and when i do that with the key in the on position it shuts down. When i turn the key off it  runs

 

off i have continuity at terminal g-m nothing at "a"

on i have nothing except continutiy at the "m" and start i have continuty at the trigger

 

i also saw this in the mix of tryig to wire everythig... what is it??

IMG_3380.JPG.ba1212b64494728bc1a0b0b35677c48c.JPG

 

 

Thanks everyone

Edited by 1.big.l
Mis typed info

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My son was driving a little Nissan Altima, we had purchased from the original owner of the vehicle, for him to drive while going to college and working part-time.  He came in one night from work (or classes, since he did have some night classes from semester to semester), and told me his car had a problem.  I asked him what was that, and he said it would not turn off (shut down).  I told him just turn the key off, and he handed me the keys.  We went outside and sure enough the Nissan was sitting in the driveway still purring like a kitten!  It took some toying with the ignition switch, before I finally got it to shut down as it should.  I anticipated having to replace the ignition switch, but apparently it was just a glitch, because he never had anymore problems with the switch.  

 

May you will be just as lucky with the Horse! 

 

I have a '95 312-8 with a Kohler Magnum Model:  M12S Engine, Serial No:  2501601673, Spec No:  471527.  I don't recall seeing anything that looks quite like that, but I will look my horse over Saturday morning and get back with you.  Looking through the Electrical System Parts Catalog for my Wheel Horse, nothing matches that design.  I will venture a guess that it is most likely a relay, but I have been known to be wrong.

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The tractor model number and serial number off the decal under the left side of the seat should take us to the correct wiring diagram.

Failing that all the numbers off the engine decal.

This is the most common ignition switch for the M12 engines

Click on each photo to enlarge them. The first one has the pinout test.

 

Be very careful to make sure no battery power gets to the ignition wire. That will burn up the ignition coil.

 

Garry

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Posted (edited)

being that the wiring diagram,what were discussing and what i see. there is no continuity from the ground to the accesories, (i can never spell that word right sorry hahah) only from ground to the magneto.

 

with the key on theres is only continuity from the batt. to the magneto, and nothing from battery to acc. or batt to regulator. or regulator to acc. 

 

sounds like i have a bad switch.

Edited by 1.big.l

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still need to ifure out what that box is.....

has 3 posts they're labeled  s, b, and h

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Without a model number can only guess it is the low-oil relay which is in the starter motor circuit. Has nothing to do with the ignition.

Click on the first picture

Adding - the reason the first picture shows one terminal going to the magneto is this relay was first used as an isolation relay to control the magneto ignition with a battery ignition switch in the early 1980's. This will not apply to a 312-8 model for use in the ignition.

The 1986 single cylinder Kohler engines used the relay in the low oil starter circuit starting in 1986.

 

Garry

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Couple of basic questions. Did this tractor ever run with the ignition switch and wiring as shown? You say that you have continuity from "B" to M", that is not good, may have already damaged the Magneto. 

This item appears to be a relay, where do the two connected wires go, and where did the third wire go?

IMG_3380.JPG.ba1212b64494728bc1a0b0b35677c48c.JPG

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It's Saturday morning and I am not moving that swift this morning, but I have looked my 312-8 over.  There is nothing that looks like what you have pictured on it.

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The 1985 single cylinder Kohler's did not have the low oil starter circuit.

The relay was first used in 1986 for the low oil starter circuit.

 

Garry

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thanks everyone for your response. i have told my friend to order a new key, and get a new battery and everything should be fine .

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