Snapper Safety interlock

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  #1  
Old 09-09-07, 12:45 PM
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Question Snapper safety cutoff...

Hey Guys...newbie here looking for a bit of help. I have a Snapper rear engine rider. After I hosed it down, it won't let me put it in gear without quiting. Neither will it let me engage the blade, even in nuetral, it will die. I found a red wire on a common terminal with a black wire, when disconnected it runs/works like advertized. The other end of the red wire goes to a half-dollar size, 3/4 inch thick round sealed item near the starter solenoid. Also going into this magic round piece are the wires coming from the neutral switch. The other end of the black wire (on the common terminal) goes up to the coil. I assume this round item is a safety switch and it seems like mine might be bad, right? Any ideas?

Randy
Georgia
 
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  #2  
Old 09-09-07, 04:04 PM
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You've disconnected the kill circuit wiring in complete fashion by removing the red wire from the junction block. This doesn't pinpoint any particular area of trouble and without knowledge of the mower model & serial or the wiring schematic it will be near impossible to help you determine the exact area of trouble. The half-dollar size component should be a relay switch and could be your trouble but may not be.
 
  #3  
Old 09-09-07, 09:08 PM
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Sounds like you have either a bad seat switch or the connection to it, or the interlock transistor you unplugged is bad. It's about $45 for a new one. I also noticed that when they go bad, it's often when they got wet.
 
  #4  
Old 09-11-07, 10:55 AM
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thanks...so far!

Thanks, Folks. There is no seat switch on this model. I first thought of that and actually removed the seat to check, and nope..not one. And it was right after I hosed it down that the problem occured so perhaps it is that relay. But how does it know when to 'NOT' let the machine go into gear or engage the blade if there is no seat switch? What tells it that I'm sitting on it and it's okay to allow these functions? Just what is an 'interlock transistor' and how does it work?

Randy Gibson
 
  #5  
Old 09-11-07, 10:10 PM
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I can't recall the manufacturers name for it, but I'm sure it's not interlock transistor. It's what Puey is referring to....I think it is a transistor rather than a relay (has only 3 legs and is encased in some kind of gum or plastic), but I could be mistaken. In either case, it's a safety interlock. It senses the position of the safety switches and grounds the coil accordingly, so it won't start if the blades are engaged, or tranny is in gear, etc...
 
  #6  
Old 09-12-07, 02:25 AM
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Find the model plate (probably actually a sticker) and post back with the model and serial number of your machine and I can do a lookup of wiring schematic and be better able to help you out. The sticker will most likely be below the seat area of the frame.
 
  #7  
Old 09-12-07, 06:24 AM
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found the model...

Finally! I found it. Model 281213BE Serial 45842920.

And the red wire I disconnected goes to a half-dollar size, 3/4" thick round item with three wires going into it and then it appears to be filled with an expoxy of some sort, so I can't see what the three wires attach to. Of the three wires going into this unit, one is the questionable red wire, one is coming from the nuetral switch and the other dissappears under the frame. Thanks for the help, guys!

Randy Gibson
 
  #8  
Old 09-15-07, 04:17 PM
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Snapper Safety interlock

Model 281213BE Serial 45842920.

Hi Folks. this is a follow up post. This think acts like it has a seat interlock switch but it doesn't. While running, if you move the shift lever right (as if to engage the trans) OR if you try to engage the blades, it dies. I disconnected the red wire going to the interlock (round, 3/4" thick under seat near starter solenoid) and it works fine. This started after washing. Question is, since it doesn't have a seat switch, what is this thing 'seeing' that tells it that it isn't safe to go or mow? My dealer doesn't know and says there is no clutch switch on this model either. He just wants to sell me a new interlock switch (at $36) and says to try it. Any ideas?

Randy
Georgia
 
  #9  
Old 09-15-07, 09:18 PM
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It's bad.

There is no manual or explanation of this module and how it works that I know of. It's a simple transistor set as far as I know. It keeps the coil from firing if the shifter isn't in neutral, or if the blades are on...unless the engine is running. It is sensing the position of the two safety switches, and the voltage at the coil kill wire. As far as I can figure, when it senses the voltage in the coil at the kill wire (meaning the engine is running), it switches out the transistor that allows the current to pass to ground when the safety switches are activated. When that current in the kill wire is gone (engine is not running), it allows the safety switches to work. When you unplug the red wire, you are disabling the entire safety system altogether. This module isn't "seeing" anything that tells it it's not safe to mow. It's actually NOT seeing something. That's the fact that the engine is running. And it may be seeing that, but unable to make the switch. It's semiconductors...they go bad on occasion.

I'm not sure if you got what your after, but that's as far as I can go with this one.
 
  #10  
Old 09-16-07, 06:33 AM
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I hadn't thought of that...

I get it. It's not 'seeing' that the engine is running and it's okay to go and mow. And I'll admit I don't know enough about semiconductors to understand them so, I'll just replace the interlock and see what happens. I'd rather not leave the safety lock-outs out of the system in case someone other than me mows so I'll replace it. Thanks for all your help! I'll post again after replacing to verify it's fixed.

Randy
Georgia
 
  #11  
Old 08-23-10, 05:52 AM
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How did you fix it?

Hi Airbusboy,

Where you able to fix this problem? I am having the same issue.

Thanks for help in advance.
Amol
 
  #12  
Old 05-14-11, 08:27 PM
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Series 6 Snapper

Good Evening folks,

Just read your posts on the same issue an elderly neighbor of mine is having. His 12HP Snapper Series 6 will not run unless we disconnect the red wire/half moon clip from the grounding post on the engine block.

I got into the safety switch box and disconnected the safety switch wires to try an isolate the issue. Seems to be coming from the round "switch relay" people have been referring to in the previous posts. Mower will start right up unless that red wire is connected to the post. Even if I disconnect the safety switch wires that round module seems to be the culprit.

Any advice would be greatly appreciated. I'm trying to fix this for my elderly neighbor so the mower will still be safe to use, but also so he doesn't get hosed on additional unnecessary repairs.


Thanks in advance!

Joe T.
 
  #13  
Old 05-17-11, 08:38 PM
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Sounds like your interlock module is bad too.
 
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