Mower PTO will not disengage

[daydremer152]

First post in this forum....Thanks in advance for help opinions...

Craftsman 917.273220 from 1998. Hand me down from wife's stepfather.

Spent much time and considerable monies keeping it going. Replacing it is out of the question right now.

Here's today's problem....PTO will not disengage...control panel switch has no effect....disconnect switch (pull plug) and tractor will not start...WITH SWITCH OFF OPERATOR CANNOT LEAVE SEAT or unit will die...this had not been this way before....if PTO was engaged it would shut down....if it was OFF it would continue to run....haven't had time to do further diagnostics but....the only combination of causes I can fathom is a bad switch.....a bad PTO bearing would not affect the running without an operator....no wiring schematic is available to see if a shorted wire could confuse the safety mechanisms AND cause the PTO to remain engaged...

Thoughts.....

Thanks again...

 

[TonyMcD]

Hard to make heads or tails from it, but here's the schematic > > > http://www.searspartsdirect.com/par...7/1509200/10059495/00001?blt=06&prst=&shdMod=

Not sure, might be the pto switch (50) or the Operations Presents relay (81) or interlock switch (16) ..... or a wire somewhere.

Hope this helps

 

[daydremer152]

Thanks for the reply Tony as I have never seen a wiring diagram this is what I see.....

seat switch is obviously working as designed....get off the seat and the engine stalls.....relay I think should only allow current to pass when there is an operator present....it appears to be working as planned...when operator gets off it stalls....so the current is getting through and turning off when seat switch is released.....I wish I knew how the internal switch "wiring" was done....as it appears it doesn't stop sending current to the PTO and through the seat sensor circuit....

If someone has or has seen the wiring diagram and can point me in the right direction it would be appreciated

Thanks

 

[mostly_gas]

Does the electric PTO remained engaged when you throw the PTO switch?

 

[mostly_gas]

If the PTO responds to the PTO switch then look at the operator relay (81). Sometimes there will be a quickie diagram on how the relay works. If the relay appears ok check the wiring feeding the relay. If the PTO is not responding to the PTO switch then start there.

 

[daydremer152]

Thanks for the reply mostly gas....

Yes the PTO remains engaged regardless of PTO switch position....hope to be able to do some more complete checking over the weekend if the weather cooperates. Need to get the situation understood and be ready to implement the fix........the lawn waits on no man.......

Thanks

 

[mostly_gas]

Really sounds like the PTO switch is gone. All your other problems are likely due to the fact the safety system "knows" the pto is not disengaged.