Engine will not crank

[Jeff Hickman 2]

I have a Wheel Horse that i bought around 15 to 20 years ago.  It had a B&S 28q777 engine that suffered some severe damage and cracked block.  So, i bought a new B&S 31R977 for around $500 and replaced it.  The replacement was not too difficult and after modifying the wiring slightly (The old engine used AC to power the headlights.  The new engine uses DC,) every thing worked fine.  The old headlight used 2 25 watt incandescent bulbs and were essentially worthless.  So, I bought and Auxbeam light bar for around $30 and put it on the tractor.  I had to rerun the wires to avoid the muffler and now the tractor won't crank.  Thought it might be the battery.  So I recharged it and still no luck.  When i turn the ignition to start, i get 12 volts on the orange wire on the solenoid, but I also get 12 volts on the green wire on the solenoid.  It is not getting grounded.  When i temporarily tie the green wire terminal to ground and turn the ignition, it starts.  I thought maybe the kill relay was defective and replaced it.  Still does not work.  Tomorrow, i plan to see if the yellow wire the kill relay is getting 12 volts. If it is, I will then see if the brown wire on the kill relay is grounded or floating.  If the brown wire on the kill relay (connecting to the NMIR) is floating, then i think the NMIR module is defective and i will have to replace it. 

 

Any thoughts or critiques?

[Pullstart 65,793]

Hi Jeff, 

 

What is the model of your tractor?  A proper wiring diagram would be step 1 in my book.

[953 nut 59,252]

I'm going to take a wild guess here and see where it goes. If this a new replacement solenoid one of the small terminals needs to be grounded.

[Jeff Hickman 2]

My Wheel Horse is a 16-38 HXL Model 71227.  I have a copy of the wiring diagram.  It is attached.

 

Jeff

 

 

Wheel Horse Wiring Diagram.pdf

[Jeff Hickman 2]

It is not a replacement solenoid and according to the wiring diagram, it gets its ground thru the Kill Relay and the Kill Relay is controlled by the NMIR module.

[oliver2-44 10,584]

[Tractorhead 9,185]

Hi jeff and  to 

 

 

you told you have rerouted some wires, 

so i would check if you accidentally removed a needed ground wire,

 

next check the Clutch switch.

 

[gwest_ca-(File Mod) 11,392]

Added some color and will do more as time permits

 

Garry

 

Adding

Made a change to the internal NMIR wiring so it is easier to understand so replaced the original illustrations I posted.

 

 

 

 

[gwest_ca-(File Mod) 11,392]

6 page pdf completed

Garry

[Jeff Hickman 2]

It turns out the problem was a sticking relay in the NMIR module. I pulled the NMIR module out and applied 12 volts directly to the tabs.  I could hear the relay clicking and verified i had connection with a continuity tester.  When i go that unstuck, everything works fine.

 

Although it is working right now, i am going to try to find a new NMIR module and replace it.  if I can't find a reasonably priced replacement, I will just bypass the module.

[953 nut 59,252]

3 hours ago, Jeff Hickman said:

I will just bypass the module.

Just look before backing while mowing, which I'm sure you do anyway.