I have a John Deere 100 series riding mower. I have had it for about 10 years and never had a problem with it other than replacing the battery. I was just outside cutting the grass and the blades disengaged and stopped turning. There is a yellow knob to the right of the steering wheel that controls the drive belt. I pushed the knob in and pulled it back out to engage the blades and they started turning for about 3 seconds and disengaged again. Now it will not engage at all. The belt is not broken or off the pulleys. I am a do it yourselfer, so I am going to start troubleshooting but I thought I would post on here and see if someone has experienced this and what the fix was.
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Need help with a John Deere riding mower
- Thread starter johnmr12
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Export threadI pushed the knob in and pulled it back out to engage the blades and they started turning for about 3 seconds and disengaged again. Now it will not engage at all. The belt is not broken or off the pulleys. I am a do it yourselfer, so I am going to start troubleshooting but I thought I would post on here and see if someone has experienced this and what the fix was.
Mower clutches are typically controlled mechanically or electrically. My two self propelled mowers are one of each.
Does it stay engaged longer if you hold/pull firmly on the knob? If so, that suggests a mechanical belt tension issue (too loose), with something out of adjustment or damaged in the mechanism that holds the belt in it's engaged position. Mechanical mechanisms (when engaged) are typically an idler pulley being held against the belt by spring tension. There are also some systems with mechanical clutch friction plates and pressure springs.
If yours is an electric clutch, check any safety switches that may have loose wiring, or are not in proper contact with the safety item they are monitoring (i.e. your weight in the seat, transmission lever in a certain position, etc). Check the wiring has not become disconnected at the clutch magnet, and that the ground wire running from the clutch magnet to ground (typically the engine or frame) is also connected. Check for any burned fuses in the clutch wiring harness.
Check all four surfaces, the entire length of your belt to make sure there are no chunks missing out of it. Belts don't always cut completely through and fall off the sheaves when they fail.
Mower clutches are typically controlled mechanically or electrically. My two self propelled mowers are one of each.
Does it stay engaged longer if you hold/pull firmly on the knob? If so, that suggests a mechanical belt tension issue (too loose), with something out of adjustment or damaged in the mechanism that holds the belt in it's engaged position. Mechanical mechanisms (when engaged) are typically an idler pulley being held against the belt by spring tension. There are also some systems with mechanical clutch friction plates and pressure springs.
If yours is an electric clutch, check any safety switches that may have loose wiring, or are not in proper contact with the safety item they are monitoring (i.e. your weight in the seat, transmission lever in a certain position, etc). Check the wiring has not become disconnected at the clutch magnet, and that the ground wire running from the clutch magnet to ground (typically the engine or frame) is also connected. Check for any burned fuses in the clutch wiring harness.
Check all four surfaces, the entire length of your belt to make sure there are no chunks missing out of it. Belts don't always cut completely through and fall off the sheaves when they fail.
Thanks for the reply. My clutch is electrical. I have a knob near the steering wheel that sends voltage to the clutch when I pull the knob up. When it first failed, I was able to disengage and then pull the knob back up and it engaged again for only a few seconds. Now it will not engage no matter what I try. I pulled on the knob, tapped it with a screwdriver, then I engaged it and tapped the clutch. I jiggled the wires. I was hoping to find the cause that way but it is dead in the water. The belt is fine, the 3 wires coming from the clutch go into a harness. None are attached to ground on the chassis underneath. I pulled gently on all 3 wires thinking if one had come loose it would have some play in it, but they are tight. I checked all the connections for other circuits. I am not sure which connections are for safety but I checked them all.At this point I am thinking it's either a bad switch or a bad clutch. The switch has several contacts so I assume it is not only sending voltage to the clutch but also to the safety circuits, telling them that the blades are engaged. The clutch is about $150, and the switch is about $15. If I had a schematic drawing of the switch circuit I could put a jumper wire on the contacts that send power to the clutch. I could also see if I have a short in the switch that is telling one of the safety circuits that I am not in my seat.
Thanks for the reply. My clutch is electrical. I have a knob near the steering wheel that sends voltage to the clutch when I pull the knob up. When it first failed, I was able to disengage and then pull the knob back up and it engaged again for only a few seconds. Now it will not engage no matter what I try. I pulled on the knob, tapped it with a screwdriver, then I engaged it and tapped the clutch. I jiggled the wires. I was hoping to find the cause that way but it is dead in the water. The belt is fine, the 3 wires coming from the clutch go into a harness. None are attached to ground on the chassis underneath. I pulled gently on all 3 wires thinking if one had come loose it would have some play in it, but they are tight. I checked all the connections for other circuits. I am not sure which connections are for safety but I checked them all.At this point I am thinking it's either a bad switch or a bad clutch. The switch has several contacts so I assume it is not only sending voltage to the clutch but also to the safety circuits, telling them that the blades are engaged. The clutch is about $150, and the switch is about $15. If I had a schematic drawing of the switch circuit I could put a jumper wire on the contacts that send power to the clutch. I could also see if I have a short in the switch that is telling one of the safety circuits that I am not in my seat.
I found a you tube video where someone showed how to test the PTO switch with a meter. Mine tests good, so it looks like it's the clutch.
bertsmobile1
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From what you have posted you would be well advised to buy the J-D factory technical manual.
It will pay for itself in no time flat.
Next you say the clutch has 3 wires AFAIK the clutch should only have 2 wires, both black as the clutch used on 100 series tractor mowers is not polarity sensative
This is assuming you have a 100 series tractor type mower and not a 100 series Rear Engined Rider ( RER )
not sure what you watched on EWE Tube but you really can not test a PTO switch with a multimeter as it is a high load carrying switch and most will show continuity but not have enough contact to carry 3-5 Amps.
Hopefully the shaved monkey on the tube identified the various sets of contacts.
The bottom 2 ( yellow wires ) should be the PTO contacts the others are a kill switch ( white) & a cranking circuit switch ( purple) .
The switch is a simple sliding switch which bridges or opens the contacts left to right.
Thus you can bypass the switch by bridging the yellow wires at the plug.
Clutch activates = switch is duff
clutch does not activate = wiring problem
To test the switch properly hook it up to a headlamp & battery so you have a load on the switch.
There is nothing whatsoever in the clutch circuit other than the clutch switch and the mow in reverse switch ( where fitted )
It will pay for itself in no time flat.
Next you say the clutch has 3 wires AFAIK the clutch should only have 2 wires, both black as the clutch used on 100 series tractor mowers is not polarity sensative
This is assuming you have a 100 series tractor type mower and not a 100 series Rear Engined Rider ( RER )
not sure what you watched on EWE Tube but you really can not test a PTO switch with a multimeter as it is a high load carrying switch and most will show continuity but not have enough contact to carry 3-5 Amps.
Hopefully the shaved monkey on the tube identified the various sets of contacts.
The bottom 2 ( yellow wires ) should be the PTO contacts the others are a kill switch ( white) & a cranking circuit switch ( purple) .
The switch is a simple sliding switch which bridges or opens the contacts left to right.
Thus you can bypass the switch by bridging the yellow wires at the plug.
Clutch activates = switch is duff
clutch does not activate = wiring problem
To test the switch properly hook it up to a headlamp & battery so you have a load on the switch.
There is nothing whatsoever in the clutch circuit other than the clutch switch and the mow in reverse switch ( where fitted )
\From what you have posted you would be well advised to buy the J-D factory technical manual.
It will pay for itself in no time flat.
Next you say the clutch has 3 wires AFAIK the clutch should only have 2 wires, both black as the clutch used on 100 series tractor mowers is not polarity sensative
This is assuming you have a 100 series tractor type mower and not a 100 series Rear Engined Rider ( RER )
not sure what you watched on EWE Tube but you really can not test a PTO switch with a multimeter as it is a high load carrying switch and most will show continuity but not have enough contact to carry 3-5 Amps.
Hopefully the shaved monkey on the tube identified the various sets of contacts.
The bottom 2 ( yellow wires ) should be the PTO contacts the others are a kill switch ( white) & a cranking circuit switch ( purple) .
The switch is a simple sliding switch which bridges or opens the contacts left to right.
Thus you can bypass the switch by bridging the yellow wires at the plug.
Clutch activates = switch is duff
clutch does not activate = wiring problem
To test the switch properly hook it up to a headlamp & battery so you have a load on the switch.
There is nothing whatsoever in the clutch circuit other than the clutch switch and the mow in reverse switch ( where fitted )
Thanks for taking the time to reply. The switch test was basically checking that the first terminal on the top left was a closed circuit with the first terminal on the top right, then open when the switch is pulled. The same test was done with the middle outer terminals and the bottom. There were a couple of other tests using the two middle terminals. Bottom line is my readings all matched the readings that the video said I should have, so I began to focus on the clutch assembly. Originally I had made sure the connector was pushed on tight. It does have 3 wires. It has a yellow wire going to one terminal and two black wires going to the same terminal. That is where I had my problem. I discovered it when I decided to pull the plug off the clutch and make sure the connectors inside were good. As soon as I pulled the plug off, one of the black wires came off the plug. I wasn't sure if I had done it when I pulled on the connector or if it was already loose, so I was able to crimp and solder the wires back on and when I tried it everything worked. I did notice some thing strange though while I was under there looking. There is only one black bracket holding the clutch steady, even though it looks like it has a slotted groove on the other side for a second bracket and it also has holes in the frame for the bolt to hold the bracket. When I looked at new clutch assemblies on amazon, I had noticed that they were including 2 brackets with the new clutch. I'm wondering if I lost a bracket at some point and never noticed or if this unit only uses one bracket. I do notice when I pull the knob to engage the clutch, the whole deck shakes hard until it engages. I'm wondering if I need another bracket and if that jarring motion everytime I engage the unit may be what caused that wire to get loose.
bertsmobile1
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\
Thanks for taking the time to reply. The switch test was basically checking that the first terminal on the top left was a closed circuit with the first terminal on the top right, then open when the switch is pulled. The same test was done with the middle outer terminals and the bottom. There were a couple of other tests using the two middle terminals. Bottom line is my readings all matched the readings that the video said I should have, so I began to focus on the clutch assembly. Originally I had made sure the connector was pushed on tight. It does have 3 wires. It has a yellow wire going to one terminal and two black wires going to the same terminal. That is where I had my problem. I discovered it when I decided to pull the plug off the clutch and make sure the connectors inside were good. As soon as I pulled the plug off, one of the black wires came off the plug. I wasn't sure if I had done it when I pulled on the connector or if it was already loose, so I was able to crimp and solder the wires back on and when I tried it everything worked. I did notice some thing strange though while I was under there looking. There is only one black bracket holding the clutch steady, even though it looks like it has a slotted groove on the other side for a second bracket and it also has holes in the frame for the bolt to hold the bracket. When I looked at new clutch assemblies on amazon, I had noticed that they were including 2 brackets with the new clutch. I'm wondering if I lost a bracket at some point and never noticed or if this unit only uses one bracket. I do notice when I pull the knob to engage the clutch, the whole deck shakes hard until it engages. I'm wondering if I need another bracket and if that jarring motion everytime I engage the unit may be what caused that wire to get loose.
One bracket is correct the clutch is used on a lot of different mowers.
Two wire to one terminal threw me