Ignition switch 92-6785/. Hot wire?

[stumplifter 9]

520 XI model 73542

Found several replacements online.  I need an ignition switch now. 
Does anyone know if the Napa SME 701891 is an acceptable replacement?

https://www.napaonline.com/en/p/SME701891

4 position 5 terminal.

 

 

Alternatively is there a way to “hot wire” this machine?  Grass is high and I need to get to cutting. 

[gwest_ca-(File Mod) 11,046]

Hot wire is a bad term. Your ignition requires no battery power and if it gets some it will go up in smoke.

The ignition works when the ignition wire is not connected to anything. Ground the ignition wire to shut the ignition off.

 

Download this file. Each circuit has it's own diagram so you can follow the circuits from start to finish.

 

[stumplifter 9]

I really appreciate your advice and the schematic.  
I am one step removed from being Amish (read: electricity is magic to me).  I certainly don’t want to fry the starter or anything else.  
Looking at the schematic makes me think I need one jumper for the ‘run’ mode and a second jumper to ‘crank/ start’ which would then need to be rapidly removed once engine fires.  

 

Hoping that the local Napa store has one (need to wait until tomorrow am to call them).

[stumplifter 9]

Nope.  Revisiting the schematic I can’t wrap my head around how I keep the B I R terminals ‘jumped’ while bumping the S terminal to start.   
 

please Napa please!

[gwest_ca-(File Mod) 11,046]

I apologize for not having the color version of the wiring uploaded. It is now so download that one.

Have you determined the ignition switch has failed?

If not -

What I would do is identify each relay and label them. Suspect the only way to do that is to use the wire colors going to each relay.

Then with a test light or voltmeter follow the wiring from battery to ignition switch and ignition switch to relays and then starter. Follow the circuit point to point across each component.

 

The important thing is do not allow any battery power to get to the white ignition wire at the kill relay. That's the one that will release the smoke.

 

Let us know what you find.

[953 nut 55,292]

Rather than replacing parts you may not nee lets start with an understanding of what is and is not working and go from there.

If you turn the key to run and turn the lights on are they bright?

When you turn the key to start what happens?

Have you removed, tested and cleaned all of your fuses and fuse holders?

Have you taken the battery to an auto parts store to have it load tested?

Have you cleaned and tightened ALL wiring terminals including grounds?

Simple maintenance steps are likely to get you back out on the lawn.

 

[stumplifter 9]

Thanks for all the input.   I tested the voltage on the battery it is 12.6.  Wife was up here last week and after cutting tried to restart with nothing.  This is a remote property, I am stealing WiFi from in town.   
 

I put my key in and there is nothing, no lights, no click, nothing.  By passed seat switch nothing.  Engaged / disengaged blades, nothing.  Took switch out and in the middle of the switch where the key goes in the cast metal part is cracked.  Ass-u-me that this is my problem.  Have new switch in hand from Napa.  Will install.  If it goes good I won’t be replying till Monday or Tuesday.   No news is good news.  
 

side note. 2 years ago I removed, cleaned and added die-electric grease to all connectors.  Feel confident on solid connections.

 

thanks again, really appreciate this community.

[gwest_ca-(File Mod) 11,046]

I don't think that is the correct switch. States it is for magneto ignition.

Your tractor has a battery style ignition switch that controls a kill relay for magneto ignition.

Big difference.

[stumplifter 9]

On 7/5/2024 at 4:22 PM, gwest_ca said:

I don't think that is the correct switch. States it is for magneto ignition.

Your tractor has a battery style ignition switch that controls a kill relay for magneto ignition.

Big difference.

 

YES! It is NOT correct, which is verified by the two pictures below showing how the terminals are ‘connected’ on the back.  Note the ‘jumper’ on the top right terminal of OEM and the ‘jumper’ is on the left of the NAPA.

 

Installed new switch and actually heard a “click” near starter but nothing else.  No lights, no whirr, nada.  Checked fuses (10, 10, 25 & 30) as well as the inline one by the starter.  All good.

20 minutes from town, to get back to internet.  Late in the day and frustrated, went in to have dinner and a pity party.   Finished and reflecting on the fact that some of the fuse connections looked ‘dirty’.  Went back out, put original ignition back in, tried it and nothing.  Removed fuses, cleaned contacts.  Removed relays and cleaned contacts.  Recognized that the dielectric grease attracts dirt/ dust used air and ‘blew out’ (or blew in deeper?) debris near fuses/ relay sockets.

 

sat down, turned key and IT’S ALIVE!!!!

 

kinda, sorta.

 

Grass was wet and daylight was fading.  Saturday was dry, got out, and machine started up perfectly.  Spent a long day cutting as some areas need double-pass as the grass was very high.  Stopped several times for lunch and breaks and machine started fine each time.  Finished for the day parked machine and cleaned off machine and under deck.   Typically lift hood, remove engine side covers and use air to blow out grass clipping/ dirt/ dust.  Raise deck and reach under with scrapper to clean off any build up clumps.  
 

About an hour after turning machine off I went to restart it to move it back into its storage area.   Neglected to to raise throttle and choke controls (normally these are both raised to start and choke can be turned off right away)… machine cranked and did not fire.   Realized my error (blaming it on a long day in the sun) and raised throttle/ choke and got NOTHING!!!

no lights, no click, no whirr.

Cursed the gods.   Tried again, nothing.  Opened hood, pressed on 4 fuses and pressed/ wiggled 3 relays to make sure everything was seated (nothing appeared to be loose).   Machine started up!!!

 

Turned it off, let it sit started again, drove around a bit, rinse lather repeat and for 4 different occasions it has started fine.

 

I have FAILED at isolating the “no power” scenario.  
 

@gwest_ca I understand the value of not releasing The Smoke.  
 

As mentioned my electric skills are one notch above Amish.   
is there a way to check the relays (they appear to be identical) by removing them and checking contacts?   Pic of my multi-meter attached.

 

Is there a better way to clean the blade receptacles then blowing compressed air at them?

 

Do I wait for another failure and trace continuity as described above whilst in the failed state?