[Brian LT133]

Hi All,

I acquired an LT133 that sat for the last 3 years due to electrical issues. The owner was told it would cost $850 then to fix it so he gave up on it. I'm excited to tackle this electrical fix since the rest of this Mower is in amazing condition and I really need a riding mower.

I pressure washed it and then leaf blowed it to dry it quicker and to not let water sit to long on any metal/electrical parts. Overall this mower looks in amazing condition for a 21 year, or more, old mower.

Before even starting it I bought the following...

The 12V 300CCA battery was dead, even after trickle charging it, so I bought a new 12V 300CCA battery.
I bought a new 3-position JD ignition switch since taking apart the old one revealed it was filthy inside the housing and their cheap enough to replace.
I bought a new RED JD Positive battery cable since the old one had very little of a metal connection due to the metal dissolving away.
I bought a new JD Solenoid. Cheap enough to replace.

I carefully looked the mower over before even attempting to start it.

I found 3 issues....

ISSUE 1 (found before starting it) I found that the VR melted a few wires just below the VR. Photos attached.

After cleaning up those connections, I was able to start the mower and it ran at low and high rpm smoothly BUT when I went into gear or engaged the blades it stalled out.

While it was running it also starting to overheat those melted wires again so I shut it down.

I've read that VR's overheat and many other starting issues are due to a bad ground. I traced all the wires and cleaned up all electrical connections.

ISSUE 2) I discovered a Ground Wire to/from the Seat Safety Switch cut with around 6 inches of the wire missing. I simply spliced that wire back together. 1 Photo attached.

ISSUE 3) I then discovered a Ground Wire to a Relay unplugged, wrapped in electrical tape and tucked under a bundle of wires below the Relay closest to the Solenoid. My LT133 has 2 Relays. This is the inner Relay. The outer Relay seemed to have all its connections properly secured. Photos attached.

Why would someone unplug this ground that is connected at the engine block, then goes to the relay mentioned above and then goes up to the ignition switch? Wouldn't this cause a bad ground?

I'd like to to plug it back into the Relay and start the engine to see if I have any VR overheating issues but want to wait for feedback first from anyone who can shed some light on this. I basically don't want to fry anything else on this mower.

Thoughts and Thanks so much for any feedback you can send my way.

 

[tsoleno]

You may have a few things going on here. But where I would start is checking the stator to see if it is shorted to ground. Kohler magnets under the flywheel come loose and eat the stator. My internet is a slug tonight to check you pics. The fuse should have blown. See that you have one. The regulator body should have a wire or strap to ground. Is the engine possibly loose? Bolts drop out of these, the engine shifts and has fun with that relay wiring.

 

[RandallCK]

Have you considered just going with the basic circuits required for it to run and working from there to find the problems? I recently brought home a LA110, that had severe mouse munching on the wiring and the previous user had bypassed ALL the safety switches, relays, etc., to make it run. It was a nightmare to get back to stock wiring, but at least it ran when I got it. You had to choke it to kill it, but it ran. I'm guessing the wiring issues you are running into are because one, or more of the safety switch circuits failed and the previous owner tried work arounds, that didn't work. The voltage regulator over heating may also be from a grounded wire in one of those safety circuits, that is not supposed to be grounded. The ground that runs to your ignition switch is to kill the magneto, when the switch is turned off. When that was missing from my wiring, it was why I couldn't turn off the engine with the key. Good luck with you wiring project. It's lots of fun.

 

[Brian LT133]

You may have a few things going on here. But where I would start is checking the stator to see if it is shorted to ground. Kohler magnets under the flywheel come loose and eat the stator. My internet is a slug tonight to check you pics. The fuse should have blown. See that you have one. The regulator body should have a wire or strap to ground. Is the engine possibly loose? Bolts drop out of these, the engine shifts and has fun with that relay wiring.

Thanks so much for the response! I'll take a look under the flywheel as you suggested. I was hesitant to do that since I've never done it before but I 100% agree that it can't be overlooked. I'll take pictures the before and after. I'm sure it's dirty as ever under there as well. Stay tuned and thanks again. Brian

 

[Brian LT133]

Have you considered just going with the basic circuits required for it to run and working from there to find the problems? I recently brought home a LA110, that had severe mouse munching on the wiring and the previous user had bypassed ALL the safety switches, relays, etc., to make it run. It was a nightmare to get back to stock wiring, but at least it ran when I got it. You had to choke it to kill it, but it ran. I'm guessing the wiring issues you are running into are because one, or more of the safety switch circuits failed and the previous owner tried work arounds, that didn't work. The voltage regulator over heating may also be from a grounded wire in one of those safety circuits, that is not supposed to be grounded. The ground that runs to your ignition switch is to kill the magneto, when the switch is turned off. When that was missing from my wiring, it was why I couldn't turn off the engine with the key. Good luck with you wiring project. It's lots of fun.

I agree wiring projects, especially without a "Multimeter", are not easy. I plan to buy a "Multimeter" so if you have any suggestions on one I'm all ears.

I printed out the wiring schematic for the LT133 and plan to trace each wire and connection now.

Oh and when I picked up the mower and lifted the engine a mouse jumped out from inside the engine cover so I definitely had residents who could have had a few midnight snacks on my wiring. Overall I haven't see evidence of that even after taking the engine cover off and cleaned out the mouse nest debris. I'll let you know how it goes and provide pics of any discoveries that I may find.

Thanks again! Brian

 

[rwmeyer]

Brian, A volt meter, and better yet, a multimeter, will tell you if you have a stator issue. I'm not sure which stator/charging system you have, but you'll have 2 wires coming from the stator. Set meter to AC volts & connect meter to these wires. Start engine & warm, then go full throttle and read voltage. I don't have exact spec but thinking ~around~ 24-40 volts AC. If no volts, stator or magnet issue. If volts, problem is elsewhere!

Unless you're dong electronics type work ANY multimeter will work! Harbor Freight has them for $7.00 and most box stores have them for under $50. If you get "lost" in the instructions, post make & model of meter here and we'll help ya. Bob

 

[Brian LT133]

Brian, A volt meter, and better yet, a multimeter, will tell you if you have a stator issue. I'm not sure which stator/charging system you have, but you'll have 2 wires coming from the stator. Set meter to AC volts & connect meter to these wires. Start engine & warm, then go full throttle and read voltage. I don't have exact spec but thinking ~around~ 24-40 volts AC. If no volts, stator or magnet issue. If volts, problem is elsewhere!

Unless you're dong electronics type work ANY multimeter will work! Harbor Freight has them for $7.00 and most box stores have them for under $50. If you get "lost" in the instructions, post make & model of meter here and we'll help ya. Bob

Hi Bob,
Thanks so much for this info. I'm going to buy a Multimeter soon and do this exact test. I'll still take a look under the flywheel and see if there's any damage to the stator. I also want to see under there to clean out any debris that could have caused or could cause any future failures.

This DM300 pocket sized multimeter should do the trick. DM300 Pocket Sized Digital Multimeter

I also am fixing up a 9 year old 4x8 harbor freight trailer. I'll use this multimeter on that rebuild also to make sure all my lights work and my tow connections are solid.

I'll let you all know how it goes. So far it's been fun aleit one puzzle after the next. Thanks for helping out and offering so many resources on this site! I've been reading posts on this site for over 3 weeks now!

Thanks again! Brian

 

[rwmeyer]

Brian, I don't know how much engine work you've done, but use care when removing flywheel! It looks like it's a tapered fit and they've been known to be hard to remove. Some guys have removed the spark plug and stuffed a piece of rope into the cylinder to stop rotation when removing or installing the bolt on the end of the crank holding the flywheel on. The flywheel looks like it has tapped holes for removal and you may need to make a puller plate. After removing, inspect key closely and replace if it shows ANY wear or distortion.

The meter you posted should work fine. Bob

 

[ttazzman]

^^^^ what he said on the flywheel most are a tapered shaft ..... usually a LITTLE bit of puller pressure and then a good rap on the crankshaft end where the puller is seated with a soft hammer will usually un - seat them ...

yep need a multi-meter.........i am laughing a bit because for years Harbor Freight had cheap multi-meters for free with a coupon and i would get one every time i went to HF ....then i gave them to all my family that calls me when something goes wrong with something electrical i told them now they can just call me ...and i can walk them thru some diagnostics with the multi-meter on the phone ..... its not like i dont want to help them its i just want to know what to bring with me in the way of parts if needed 😂 this thread just jogged my memory

 

[rwmeyer]

Another note! After you break the flywheel bolt loose, back it out about 1 r 2 turns, This will do 2 things: Prevent the flywheel from "popping off" too far, and also protect the threads in the end of the crank from any damage that could be caused by the puller. Bob

 

[Brian LT133]

Thanks again for all this advice! I've never pulled a flywheel off so this is all new to me. To be safe, I'll call my neighbor named "Bob" who I'm going to ask to borrow a puller and also ask if he'll help me get the flywheel off.

I'm hopefully heading to Harbor Freight today to get the multimeter, a heat gun, angle grinder (for another project that I'm tackling. Basically rehab'ing a 4x8 Harbor Freight trailer I got 2 months ago) and a few other toys. )

Thanks again! Brian

 

[RandallCK]

Good luck getting the flywheel off. Not being sarcastic, it's just they can be a real PITA. Harbor Freight has started selling some decent tools. I bought one of their Hercules angle grinders a couple of years ago. A well made tool, but the small plastic slide switch broke and there are no parts available. I happened to have another one that launched itself to an untimely death, so I was able to salvage the switch from it. If they ever start offering a complete catalog of replacement parts, I'll consider them for more power tools that I plan on using long term. I'm up to four angle grinders now, so it probably won't be one of those.

 

[rwmeyer]

Brian, Hmm, I just thought of something else that you may need! I don't know what type of puller "Bob" has, but if it's the 3 jaw type, it'll have to be pretty big. If it's the "bearing separator" type, hopefully he'll have a "strongback" too.... a long, narrow H looking thing with a tapped hole & screw in center. Check the tapped holes in the flywheel as they may be metric! Get bolts while you're out! Bob

 

[Brian LT133]

Hi all,
We'll it's nearly a year later and I'm finally getting back to fixing my JD LT133. Yes, it's been sitting cold ever since I reached out to you all last June. Life, wife, kids, work, etc... seem to get in the way.

Last June I ended up replacing the Voltage Regulator but the Brown wire that burned previously was still overheating when I started the mower. I shut off the mower and stored it for a year.

Yesterday, I finally cut off an inch of the bad Brown wire, spliced it, crimped it, and jump started the mower with a screwdriver across the Solenoid. It ran beautifully at high and low speed.

The mower stalled when I tried to drive forward and take my foot off the brake.

Then I discovered the headlights didn't work unless I jiggled the “0.5 sq mm fusible link wire.” That wire also sparked when I jiggled it. I'd like to replace the “0.5 sq mm fusible link wire.”

Can you recommend a replacement to the “0.5 sq mm fusible link wire”? There's no physical 15amp or 20amp fuse on this mower but wouldn't it be a good idea to add one?

Thanks again! Brian

PS - photos of my wiring work attached and photos of the bad “0.5 sq mm fusible link wire” attached.

 

[Frogmore]

Did you figure out where the brown wire goes?
I don't have a schematic for your machine, but it looks like it is using AC for the headlights (which some machines do). Normally, the white wires are from the charging coil under the flywheel. The VR takes the AC and converts it to DC. Incandescent lights will work on AC or DC.

This is an example of the fusible link wire:

PICO Wiring 5557PT Pico Fusible Link Wires | Summit Racing

Free Shipping - Pico Fusible Link Wires with qualifying orders of $99. Shop Fusible Links at Summit Racing.

www.summitracing.com

Or the Deere part

John Deere WIRE M113605

www.greenpartstore.com

If the brown wire is overheating, you have a short/overload. You need to figure out what is causing it. The fusible link gave its life to protect the rest of your tractor. Don't just replace it, find and fix the overload.

 

[denverguy]

This suggestion might be a day late and a dollar short but something to consider. John Deere LT133 Wiring Harness AM123450 | eBay

It's is often a big project fixing a wiring harness with multiple hack.