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gx345 ignition switch module burned up, why is this light staying on?

10K views 42 replies 7 participants last post by  denverguy  
#1 ·
So i was mowing the lawn and smelled what i can only describe as burning brake pads. It was so strong I thought it was a car driving by. I went to shut the mower off and empty the bags and it wouldn't shut off. the ignition didn't seem to do anything. So i finished mowing the lawn and had to pull both sparkplug wires off to get it to shut off.

Ordered part AM132500 on amazon, replaced it, and discovered this. Looks like the blue wire on the upper left of this plug got mega hot and melted some of the plug. I think the blue wire is still plugging into the pin on the board properly, but I don't know where that wire leads to to check for continuity.

I replaced the module and it fired right up, but then I noticed the oil pressure light was on, constantly. Even when i turn it off and take the key out the light stays on....Is this normal?

I haven't had time to even check oil level, let alone oil pressure, but the light being on 24/7 makes me think something else isn't working right. Anybody know what that blue wire is for, or where to find a pinout diagram?

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#2 ·
i think i've determimed the blue wire goes to the s3 RIO switch. is this the switch for the hydrostatic drive?

Is it possible that the ignition switch just burned up and caused this blue wire to get super hot, when it wasn't anything having to do down line from the blue wire itself? I finished mowing the lawn and forward reverse worked just fine.
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#3 · (Edited)
RIO is the Reverse Interlock switch - I believe from that picture, it's on the transmission not the switch on the dash. Either way, I can't see how that could be the cause of the meltdown - I think it's collateral damage.

Can you still keep the PTO engaged while backing up if you pull up on the reverse interlock?

Regarding your oil pressure light, I'd look for more collateral damage in that area - I wouldn't be surprised if the sender wire had the insulation melted and is now grounded.

EDIT: just reread your first post - it's not normal for the oil light to stay on with the key out. I would look for additional damage to the wiring harness or perhaps you have a defective ignition module.

I'd also check for a pinched wire behind the ignition module board.
 
#4 ·
EDIT: just reread your first post - it's not normal for the oil light to stay on with the key out. I would look for additional damage to the wiring harness or perhaps you have a defective ignition module.

I'd also check for a pinched wire behind the ignition module board.
I just replaced the ignition module. I'll see if there is a pinched wire behind it somehow.

Another weird thing. The oil light stays on with the key off and the 2 big plugs on the ignition module unplugged.....I guess I need to try and read the wiring diagram to see how the oil light is fed power and trace back that wire to see if its melted somewhere?
 
#8 ·
Not sure why this is more interesting to me than the slide deck that I'm should be working on but...

In looking at my book, the yellow/black wire should be feeding power to both the oil pressure and temp lights. The tan wire off the oil pressure light runs to the sender. The sender is closed when oil pressure is low which completes the ground circuit and the light goes on.

So...where is the power coming from if you have disconnected the ignition module? Does the light stay on if you disconnect the sender?
 
#10 ·
Ohh, I forgot to tell you the weirdest part. The oil light was not on when the old burned up ignition was attached. But then I replace it, connect battery, immediately get light. Unplugged two plugs from ignition, light stays on.....

Ill check the oil pressure sending unit tomorrow, got tball coaching tonight.
 
#11 ·
My GX345 decided to stop turning off when I turned off the key. I replaced the ignition module and switch assembly and also the time delay module. No luck. The oil pressure indicator light stays on and you will find the green and red lights stay on, on the ignition module Board if the brake is set. It’s like the key is set in the accessory position not the off position. Still trying to figure out what it is. There is something downstream from the ignition module that is not shutting off the engine and/or the power in general
 
#15 ·
You never replied back with any details about your previous post. Your GX345 requires power to run. Happy to help you troubleshoot but you need to provide some details on the sequence of events now that you have clarified that you have a GX345, not a GX335.
 
#17 ·
Assuming that oil pressure switch simply closes to engine/chassis ground when oil pressure is not present: Unplug the oil pressure switch, does the light go out then? If so, reconnect it and start the engine. Does the light go out with oil pressure present? If so, the switch and signal wire to the switch are working properly and your only issue is that the +12V to the light is not being cut off when the key is switched off.

Please post a schematic showing the oil light wiring all the way back to it's source, and we can help troubleshoot better from there.
 
#18 ·
oh man, i feel like 1 step forward, 2 steps back.

i'm so disgusted I hope i remembered these points correctly.

key out, connect both battery terminals, i can hear relays clicking on the ignition module and sounds like a relay near the front of the motor, both green and red lights on on the ignition module.
tractor will now start, and wont shut off without pulling spark plug wires.

so it feels like the ignition cylinder and ignition module is always on and doesn't go to off, when key is off or pulled out, maybe the "new" ignition module is also bad? like was suggested before. (i just assumed if it turned over with the new one, and it wouldn't with the old one, it was working correctly.

I don't think the oil light is actually a real problem now, because the oil light isn't technically on when the ignition is off, its like the ignition is always on...

I did unscrew the wire from the oil pressure sending unit, the oil light did go off.
 
#19 ·
Good news that the oil pressure light isn't always on - that would have been a really odd scenario.

Any chance you have a spare TDM or the procedure to test it?
 
#23 · (Edited)
Good news that the oil pressure light isn't always on - that would have been a really odd scenario.

Any chance you have a spare TDM or the procedure to test it?
ohh Time Delay Module. I don't know how to check it, but I ordered another for $18.50 shipped prime, so i'll just swap it out, if problem fixed, yay, if same issues, i'll assume both TDMs are good and move on to the next fix.

LMAO, wish i saw this photo before I ordered.
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Question.....should i spring for the John Deere original equipment one for $34.70 or the Partman one for $18.50?



EDIT: Oh man, i'm all over the place. Local dealer has one, $35 in stock, i'm canceling the Amazon order and i'll report back after I install it. FINGERS CROSSED!
 
#21 ·
TIme delay module and it is the curse of the tractor...... I know, it can drive you crazy with electrical issues. I'm not sure it would solve yours though, not heard it doing what you have happening before but who knows....Cheap enough (and easy) to replace. About $25.
 
#24 ·
Excellent, the TDM provides power to both the coils and the igniter box and is the likely culprit given you have a new ignition module.

Looks like you are on your way to replacing it but let me know if you would like a couple of quick tests before you do.
 
#25 ·
Excellent, the TDM provides power to both the coils and the igniter box and is the likely culprit given you have a new ignition module.

Looks like you are on your way to replacing it but let me know if you would like a couple of quick tests before you do.
Eh......i'll just replace it. It'll take more time to test/buy/replace, than just buy/replace and i've got some other errands to do as well so I wouldn't make a separate trip home first to test, but thanks for the offer.

You can tell me where on the tractor the TDM actually is. I don't think i've seen this hanging around anywhere.
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#27 ·
Ugh, anybody want a slightly used TDM in working condition? Lol

TDM wasn't the problem, same issues persist.

Do you have testing procedures for the ignition Cylinder? I think that's gotta be it.

Too bad I don't have a known good one, but If I can test that is it, I'll just get it swapped out with Amazon.
 
#28 · (Edited)
That's unfortunate. There should be a pink/black wire on coming off the ignition module - that should have 12v with the engine in a run state, 0v with the switch off. I would check that with the wires connected to the ignition module, then pull the connector and check the terminal on the board with the same test. I would do the same to the pink/black wire with the connector off the board.

If the terminal where the pink/black connects has 12v regardless of key position, it's a defective module.

I don't have a procedure for testing the key switch itself. The part number you provided looks like the soldered on the cylinder and the book treats that as an integrated module. Do you have the integrated unit the new part that has a connector for the key switch?
 
#32 · (Edited by Moderator)
Its official, i've entered the twilight zone. If i didn't see it with my own eyes, i wouldn't believe this.

key out, connect battery, check for 12v on lower red wire, check for 12v on upper red wire attached to board, yep, yep.

unplug lower red wire, still have power to upper red wire, HMMM

for giggles I try to start it,

IMMEDIATELY all the dash lights, lights on the ICM shut off. Oh great I think, popped a fusable link, or burned up another ICM.

Hook up lower red wire again, key in off position, no lights come on.

Turn key to ON position, lights all come on, try to start, FIRES right up, go to shut it off, it shuts off, lights go out............

So somehow I had a stuck switch/relay somewhere in the key, or ICM I believe that when I tried to start the engine with the lower red wire disconnected, it jostled it loose.........

So its bitter sweet. Yay, my gx345 works again.....but should I just replace the icm at no additional cost again with another one, as this one clearly is possessed by demons?
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#33 ·
IMHO, tough call on replacing it. I've never heard of a relay needing a break-in period but can see the potential for the contact arm to become stuck internally when the shipping company tosses it off the truck. @912targa seems like he might be having the same issue. It's always possible that there is a bad batch of relays out there as well.

Glad you were able to figure it out. Hopefully, someone on the forum can provide more definitive guidance on the relay issue.
 
#35 ·
OMG the saga continues.

hop in, fires right up oil light goes away after its started like its supposed to.

mow for 2 minutes, and because the lawn is so long, i mowed over a sticky sprinkler head that sometimes stays up. YAY.....try to find the nozzle tip that flew out of the head, no dice after 15 minutes.....

start to mow again, burning smell comes back, go to shut it off, keeps running, take lights off of my cab, and drop the nut in the grass (looked for 10 minutes, didn't find it after the next sentence), get hood open pull spark plug wires, it shuts off.......unplug that lower red wire from a few posts back, put back in, it fires up again. smell seems to be coming from the ignition key area but don't see any signs of burning...... close hood and glass, have to do the trick again with red wire, fires up, mow for 6 more minutes, all of a sudden tons of smoke pouring into cab from left side, by the TDM area.

pull hood completely off the gx345 now so i can see everything and notice this silver box.....its the cause of the fire, possibly cause of the weird ignition issues too, so its possible my ICM and TDM were both fine from the get go....

What's this silver box? I can't make out all of the part number.

EDIT: AM126304 - voltage regulator......time to replace that guy.
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#37 ·
do you think i'm risking more damage by continuing to drive it with a faulty voltage regulator for another 30 minutes while I finish mowing the lawn? I'm guessing the answer is yes. I should probably call it quits for today and replace regulator tomorrow and then finish lawn. that would be the prudent, yet annoying route to go.
 
#39 ·
A faulty VR could overcharge the battery and cause it to boil. Wait until it's replaced or you might be replacing a battery too..
 
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#41 ·
Had an LX188 with the same AM126304 regulator on it. For whatever reason that I now cannot remember, I replaced it.
Found a "less expensive" substitute and it ran without problems. I've since sold the LX188
I see that the brand I bought is no longer available, but there is another brand from

John Deere Voltage Regulator
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You can find a sub on Amazon for like $26 w/Prime.(free shipping)
Or, an OEM on Amazon for $64.55 w/Prime (free shipping)

just type in AM126304 for search
 
#42 ·
Well i think the parts gods have spoken. I replaced the voltage regulator and mowed the lawn without incident; however, they required a sacrifice for their gesture in the form of me having already thrown away the ICM and now there are bags of garbage a bag of diapers, random things in the garbage and i cant/dont want to find the ICM, so its gone.

About $265 later and i have a new ICM, TDM, and voltage regulator, I should be good for another 16 years.....knock on wood.