Small Engines (Lawn Mowers, etc.): Lawn Tractor Will Not Start, craftsman model, jumper wire

Question
Hi John.  

I have a Craftsman Model 917.254940 Lawn Tractor.  The Tractor has a few years on it (purchased in 1990) but has been well maintained and has served me well.  I went to mow the lawn the other day and when I turned the key, there was absolutely no response, not a growl, not a click, nothing.  I put a meter on the battery (new last fall) and it read 12.63 volts.

I then removed the starter switch and ran a continuity test on the different positions (off, on and start).  The test showed no continuity in off or start but did show continuity in on.  So, I figured "I need a new starter switch".  I went to the local repair shop and bought a new switch and checked it's continuity against the owner's manual and it matched perfectly.  I installed the new switch and went to start the mower.  As I turned the key to "start" position, it blew the inline fuse.

After blowing 3 fuses, I put the old switch back in the mower, set it to on, and jumpered the white wire on the solenoid to the
positive terminal of the battery and the mower started right up and runs fine.  At this point, the jumper wire is a "permanent installation" as it's the only way I can get the mower to run.

The interesting thing about all of this is that after starting the mower with the jumper wire, the key switch started working again.  I tried it several times and everything was normal.  So, I went out to mow this AM and again, nothing.  I reinstalled the jumper wire and can mow but do you have any clue what's going on?

Thanks, John

Answer
Hello John:

>>From your Description it Sounds like a Safety Switch has a Bad Connection, is Going Bad or there is a Wire in the Safety Circuit that is Grounding.
>>The Safety System on this Mower is Designed to Respond as you Described when the Blade or the Clutch Brake Safety Switch is Indicating they are Engaged so the Starter Solenoid will/can Not Engage the Starter.
>>The Following is an Instruction File for the Safety Switch System. Any Input is Appreciated.
>>The Color Code of the Wires May be Different than those I Use as a Reference in the Instruction File.
>>**PLEASE REMEMBER THAT THE INSTRUCTIONS FOR CHECKING THE SAFETY SWITCHES IS JUST THAT!!! FOR CHECKING ONLY.
>>I NEVER Suggest a Mower be Operated with a Safety Device or Switch Disconnected or Bypassed.
>>**Now. On Some Model Mowers you can Simply Unplug the Safety Switch from the Harness. On Other Models you have to Place a Jumper Wire Between the Harness Terminals (on the 4 Post Switch (Clutch/Brake) Jumper from Same Color Wire (Example: White to White) First and then Check for Fire, Now Include the Black to Black Wires if No Fire. Check the Clutch/Brake and the Blade/PTO Safety Switches First.  Then Check the Oil Guard Switch (if Applicable). Check the Seat Safety Last. Usually the Seat Safety is Not in the System for Starting the Engine. Just to Ensure Someone is in the Seat when Engaging the Transaxle and/or Blades. Use a Paper Clip or a Short Wire to Make a Jumper.**  
>>Use a Multi-meter and Check the Continuity of the Switch. The Meter should Show when the Contacts are Closed and Open. The Meter will Swing All the Way Over when the Switch Contacts are Closed and Swing Back to the Rest Point when the Switch Contacts are Open.
>>If you Hit a Snag or this Does Not Correct the Problem, I Hope to be Here if You Require More
Assistance. Hope this Helps. Let me Know What Happens, Please.
>>Have a Happy Holiday Weekend and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 5 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are
Greatly Appreciated. Thanks.

Respectfully

John