Question about John Deere L100 Series

2 Answers

Engine stops running when I engage the blades

Posted by on

  • Kprime
    Kprime Apr 18, 2015

    Hi Fred Peltier, I want to help you with your question, but I need more information from you. Can you please add details in the comment box? Hi Fred. I am working on an answer for you. Should post tomorrow.

×

2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Sergeant:

    An expert that has over 500 points.

  • John Deere Expert
  • 187 Answers

"The engine stops running when I engage the blades". I am going to assume that you do not have a frozen bearing, or two, and the cutting deck is in fine operating condition. I am also going to assume your engine is in good working order and is not simply dying under the load. That only leaves an electrical problem/solution.

Regardless of what mower you own this happens when a path is completed from the kill terminal of the coil back to ground. So diagnosing the problem amounts to tracing the ground wire and the switches it passes through. This is a somewhat complex, multi-path problem. Whenever possible, I will simplify the answer.

The ground circuit, or engine kill system, on all JD 100 series and many other mowers, is conceptually the same. This holds true whether you have an electric clutch or engage the blades manually by moving the blade lever. However there is a minor difference between the automatic transmission (Hydro tranny) and the manual transmission which we will discuss at the end. In either case, there are two possible scenarios. Your problem will be from a faulty seat switch and maybe the wiring related to that switch. OR, your problem will be the RIO Switch (part of the reverse safety system, the one on the transmission) and maybe the related wiring

Shortcut: If you want to skip all the reading and go straight to the answer, just replace your Seat Switch and your RIO Switch (the one on the tranny, not the button you push). If the wiring is good, and it usually is, your problem will be gone.

Senario #1
A white wire runs from a terminal on the coil. This is the engine kill wire. When it is grounded by any means, the coil can no longer produce spark. If your engine starts and runs this wire is fine. If your engine dies when you engage the blades, the problem is not with this wire.

The white wire goes to the Key Switch and provides a path to kill the engine when you turn the key off. Your problem is not here either (Not the Key Switch or white wire). We know this because the engine starts and runs. If this part of the system was bad the engine would not run.

This white wire branches off via another piece of white wire and runs to one terminal on the PTO switch. As long as the blade lever is down, or the PTO switch is down (electric clutch) there is no ground connection inside the PTO switch and the engine remains running. Again, there is no short in the white wire and the PTO switch is good. (Good meaning the PTO is not creating a shorted ground scenario).

When you engage the PTO, either way, an internal connection is made with a second terminal on the PTO switch. This terminal has a white wire with a black stripe (Wht/Blk). The Wht/Blk wire runs to a terminal on the RIO Latch Relay (it's a little black box with no buttons up under the dash/hood). In scenario #1, your problem has nothing to do with the Reverse Operation switches. The ground path we are currently tracing does not go through the RIO Latch, it merely passes by a terminal on that latch. How? The Wht/Blk wire is joined at the RIO latch terminal with another wire. This second wire is a black wire with a white stripe (Blk/Wht). At this point this RIO terminal is just a convenient place to tie the two wires together. Sooo, Wht/Blk turns into Blk/Wht. Don't try tracing these wires with a beer in your hand.***At this point the engine is still running and there are no "bad wires or switches". (We will come back to this terminal point later in the discussion to discuss the alternative pathway, scenario #2)

The Blk/Wht wire leaves the RIO latch terminal and goes to the Seat Switch. If the operator is on the seat and the switch is good, inside the Seat Switch there is no connecting path. However, if the operator stands up, or the switch is bad, a connection is made, internally, to the exit terminal on the seat switch, which has a solid black (blk) wire.

The blk wire runs to a terminal on the transmission RIO Switch; otherwise known as the "kill the mower if you try to mow going backwards switch". This switch is typically located on the transmission (or the gear linkage on a manual tranny). The purpose of the switch is to monitor the transmission linkage for reverse activity. At this terminal there is a second black wire. That black wire goes directly to ground. So your problem once again has nothing to do with the Reverse Operation System; it is simply a convenient place to combine the two wires. In other words, once the pathway makes it through the Seat Switch, it has a direct path to ground and your engine dies.

To sum scenario #1 all up:

  1. White wire from coil to PTO switch.
  2. Activate the PTO and Wht/Blk connects at RIO to Blk/Wht.
  3. Blk/Wht bypasses RIO Latch and goes straight to Seat switch.
  4. Seat switch bad or seat unoccupied, connection made to Blk wire.
  5. Black wire goes straight to ground.
  6. Engine dies
If your engine is running and you activate the PTO a connection for the ground path is supposed to be made. However, that connection should be interrupted while you are in the seat. BUT, if the Seat Switch fails to interrupt the pathway, BOOM, engine dies.

Senario #2
RIO = Reverse Implement Option. Fancy name for "mow while you are backing up". There are 3 elements to the reverse safety system.
  1. RIS button, the button you push to allow you to mow in reverse.
  2. RIO Latch, a black box with an electromagnetic switch that changes the ground path when you press the RIS button.
  3. RIO Switch, a switch which reacts to your reverse linkage and creates the final step in the path to ground.
Now, the other much less likely but still possible pathway, involves a problem with the RIO Switch (#3); the one on the transmission. All of scenario #1 holds true until you get to the branching wire at the RIO Latch Relay (#2). The branch line through the seat switch may be just fine, BUT there is a normally closed pathway through this RIO Latch.

As in the discussion of the original pathway, the ground path arrives at the RIO Latch via the Wht/Blk wire. In the 1st scenario it branches off via the Blk/Wht wire and heads off to the seat. In this 2nd scenario the pathway goes straight through the RIO Latch (a normally closed path) and exits a terminal, on the RIO Latch with a solid white wire. Yep, another white wire.

This white wire goes to the RIO Switch; yes the one on the transmission, where it has its very own terminal and does not have to share.

The purpose of the RIO Switch is to monitor the transmission linkage for reverse activity. Internally, the switch is normally open. This means there is normally NO path to ground; unless you attempt to go backwards. When you attempt to reverse a connection is made inside this switch. It connects the white wire with the black wire (the same black wire that comes from the seat switch) and boom, you're dead.

Should this RIO switch fail, it could be stuck in the closed position. This will not stop your engine from starting and running normally. However, it will kill the engine anytime you activate the PTO. Fortunately, there is a real simple way to test this switch. There is a slight difference in the procedure between the manual tranny and the hydro tranny.

  1. Sit in the seat.
  2. Start your engine.
  3. If manual transmission, push in and hold the brake/clutch DOWN, and shift into any forward gear. If you have a Hydro tranny leave the break/clutch UP.
  4. NOTE: if you activate the PTO at this point, an engine with your problem will die.
  5. HOLD in the backup button (RIS, reverse implement switch)
  6. WARNING: Be prepared for the blades to start.
  7. While holding down the RIS button, ACTIVATE the PTO.
  • If the blades start and the engine keeps running, the problem is your RIO Switch, yes the one on the transmission.
  • If the blades start and the engine dies, the problem is your Seat Switch.
  • NOTE: once you do this, the RIO Latch remains active and the engine will not die; even if you turn the blades on and off repeatedly. The Blades Will BE Active at all times (with the PTO on). The Rio Latch will not reset until you turn the engine off with the key. So once you have tried this test you have to turn the key off in order for your original symptoms to reappear. That's another verification that your problem is this switch.

For the Curious, why does this test work? Because the ground path through the backup safety system can be broken by holding down the RIS button which causes a ground path break inside the RIO Latch Relay. The RIS and the RIO Latch Relay work anytime you hold down the button.

The RIS switch needs a path to ground in order to work. On a manual tranny it gets this path when the clutch is fully depressed. On a hydro tranny it gets this path when the brake/clutch is fully released. Once the RIS button activates the RIO Latch, through a ground provided by the PTO, it remains active via the bypass ground at the RIO Latch terminal with the Blk/Wht wire.

The RIS and RIO Latch don't know, or care, if you are in reverse they just work when told to; and when they are activated the ground path through the reverse system is interrupted. Because the path is broken in the RIO Latch Relay, this test assumes the RIO Latch Relay, the Reverse button (RIS), and the associated wiring are in working condition.

WHEWWWW, done and done.

Posted on Apr 18, 2015

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • John Deere Master
  • 2,478 Answers

Make should your blades turn easy

Posted on Apr 18, 2015

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

What causes fuse to blow every time I try to engage blades?


To engage the blades is it a knob to an electric switch that you pull?
If so does the wire from the switch activate a electric clutch?
Is the wire damaged and shorted to the frame, is the clutch shorted. If you provide the brand name and model number I might be able to find a schematic for your mower.

Video shows an electric clutch but yours may be different but this should give you an idea of where to look. Riding Mower Electric PTO Clutch Won Engage When Hot Problem Fix

Oct 02, 2014 | Garden

2 Answers

Why does engine stop when clutch released or blades engaged?


Make sure have a good battery when you start the blades on any lawnmower it need lots of power to get it going

Jul 17, 2014 | Murray Garden

1 Answer

MTD stops running when trying to engage the blades


unhook clutch at the clutch wire plug see if the blades stop turning then ativate the switch to see if it stops it dosnt bad clutch

Jun 01, 2013 | Yard Machines MTD Gold 20 HP Lawn Tractor ...

1 Answer

Safety switch located


Micro switches will just stop the engine if the blades are engaged and the operator leaves the seat, or will stop the engine cranking if the blades are engaged, it will not stop the blades from engaging.

Sep 06, 2012 | Murray Garden

1 Answer

14sb engine running when blade clutch is engaged the lawnmower stalls.


Normally I believe this mower to have a Kawasaki engine, and the main jet and 'pilot air hole' need to be cleaned. You are running a lean condition, and when the blade is engaged, the engine does not have enough fuel to continue the extra load. A small test for this is to engage the blade and the choke at the same time. If the engine has enough fuel to continue running and engage the blade, this confirms the lean fuel condition. Cleaning those jets will solve the issue.

Nov 08, 2009 | John Deere 420,1020,2010,2020,2510,2520...

1 Answer

When deck is lowered blades do not engage


Is the belt in place that drives the blades?
Is the belt at the correct tension?
With the mower engine off.....try to turn each pulley the belt drives and on the mower deck with the mower in up position and or down....do they turn a little......this is to check for a seized bearing on one of the pulleys also look under the deck for something stuck........ jamming a blade.
Also check for the mower belt safety system (which stops the blades quickly when disengaging them) that may be stuck in stop mode.
With the mower engine running.....have some one engage the blades while you look under at the belt system....is the engine driving the belt.....is the belt driving the blades.
DO NOT TOUCH ANYTHING......MOVING OR STOPPED while the engine is trying to drive the blades.

Sep 06, 2009 | Mtd Garden

3 Answers

Once engaged and start mowing, you can mow for about 20 feet or more and then it just slows down and the engine wants to die, but stop pulling immediately and the engine catches up and goes back to full...


This actually happened to a friend of mine! I saw it! Mow about 20 feet, and had to stop, then 20 feet...well, you get the picture. It was his air filter! Stopped up pretty good. We blew it out and it worked fine.
I really hope this helps. --W/D--

Aug 15, 2009 | Swisher 60" 13 Hp Trailmower #T1360h

1 Answer

Lots of smoke when I engaged stuck blades - now runs roughly


Most likely what you did was burn one or more spots on the belt. When the blades and belt stop turning, like in tall grass, the engine doesn't stop and will burn flat spots on the belt at the engine pulley. Every time the flat spot hits a pulley, it will jump and can set up a bad vibration. Run your hand around the sides of the belt or take it off and you will feel or see the thin spot(s) on it. Replace belt.

Jun 09, 2009 | Craftsman 42 in. Deck 19.5hp Lawn Tractor

Not finding what you are looking for?
John Deere L100 Series Logo

281 people viewed this question

Ask a Question

Usually answered in minutes!

Top John Deere Garden Experts

Phil Walker
Phil Walker

Level 3 Expert

605 Answers

Tim Whalen

Level 3 Expert

3074 Answers

Matt Olenzek
Matt Olenzek

Level 2 Expert

293 Answers

Are you a John Deere Garden Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...