Electrical Starting Issue

[Dave M7040]

Your engine has a system which provides power to the engine stop solenoid to shut down the engine.

A 10 second timer provides a brief pulse of power until the engine stops.

If your engine is cranking but not starting, I suspect you are powering the engine stop solenoid and cutting off the fuel to the engine.

You probably have the wiring messed up for the relay.

Dave M7040

 

[SamR]

Your engine has a system which provides power to the engine stop solenoid to shut down the engine.

A 10 second timer provides a brief pulse of power until the engine stops.

If your engine is cranking but not starting, I suspect you are powering the engine stop solenoid and cutting off the fuel to the engine.

You probably have the wiring messed up for the relay.

Dave M7040

Hi Dave
Thanks for the reply- I answered this a couple days ago but it never posted... Anyways you are correct. I had originally tried to use the white wire since it is made to disconnect easily and had the male and female connector. This time I tried it with my black wire with the white tracer from the key switch to the white wire (86) on my relay and the yellow (87) to the starter and she hit hard and fired right up. I wasn't crazy about cutting any wires on my original harness but I do like how the original connector on the black/white wire snapped onto the connector at the starter so i may move that connector so it stays put as well as the factory one has.
Cheers

 

[Henro]

Your engine has a system which provides power to the engine stop solenoid to shut down the engine.

A 10 second timer provides a brief pulse of power until the engine stops.

If your engine is cranking but not starting, I suspect you are powering the engine stop solenoid and cutting off the fuel to the engine.

You probably have the wiring messed up for the relay.

Dave M7040

Actually, this is not the case for the BX2200. I only know because I just had my fuel cutoff solenoid fail on my BX2200. The wiring diagram shows a timer but that is used on the BX1800, not the BX2200. The BX2200 uses a solenoid with two coils in it, attached to the injector pump housing. There is a pull in coil, and a hold coil. The pull in coil is actually activated by the current that flows through the starter solenoid. The hold coil is supplied voltage via the run position of the ignition switch.

For the sake of detail, the pull in coil measures about 0.5 ohms, and the hold coil measures about 23 ohms, on a good solenoid.

Anyway, if the fuel cut off solenoid is unplugged, the engine will not turn over, as the pull in coil of the solenoid completes the circuit for the starter solenoid. This is interesting and not immediately apparent from the schematic in the workshop manual.

Just adding this info to this thread in case it might help someone in the future. Not sure if it will be of interest/help to the OP...

The key to understanding the workshop manual wiring diagram is realizing that the D722 designation means BX1800 engine and D905 means BX2200 engine.

 

[Dave M7040]

Actually, this is not the case for the BX2200. I only know because I just had my fuel cutoff solenoid fail on my BX2200. The wiring diagram shows a timer but that is used on the BX1800, not the BX2200. The BX2200 uses a solenoid with two coils in it, attached to the injector pump housing. There is a pull in coil, and a hold coil. The pull in coil is actually activated by the current that flows through the starter solenoid. The hold coil is supplied voltage via the run position of the ignition switch.

For the sake of detail, the pull in coil measures about 0.5 ohms, and the hold coil measures about 23 ohms, on a good solenoid.

Anyway, if the fuel cut off solenoid is unplugged, the engine will not turn over, as the pull in coil of the solenoid completes the circuit for the starter solenoid. This is interesting and not immediately apparent from the schematic in the workshop manual.

Just adding this info to this thread in case it might help someone in the future. Not sure if it will be of interest/help to the OP...

The key to understanding the workshop manual wiring diagram is realizing that the D722 designation means BX1800 engine and D905 means BX2200 engine.

I accept your point that the wiring diagram covers two different engines. I should have looked closer.

I do not understand your point of the pull in coil completing the starter solenoid circuit. It does not seem possible if the wiring diagram is correct.

Fortunately, whatever the owner took from my post it solved his problem.

Dave M7040

 

[David_Kb7uns]

The early BXs that use the D905 have an internal stop/run solenoid with 2 windings for run and stop. The BXs that have a --2 engine (Super Mini Series) D722, D782, D902 have an external solenoid that is powered up only to stop engine and has the timer relay.

 

[Henro]

I accept your point that the wiring diagram covers two different engines. I should have looked closer.

I do not understand your point of the pull in coil completing the starter solenoid circuit. It does not seem possible if the wiring diagram is correct.

Fortunately, whatever the owner took from my post it solved his problem.

Dave M7040

The schematic drawing is difficult to understand with respect to the circuit of the starter solenoid. If you unplug the fuel cut off solenoid, the starter will not turn over. As soon as you plug the fuel cut off solenoid back in, The starter turns over normally.

The resistance of the pull-in coil is about 0.5 ohms. If there was not a current limiter of some sort in series With this coil, it would pull close to 24 A and blow the fuse feeding it every time (but not the the main 30 amp fuse.)

I am sure this is the way it is, but I did not take the time to remove the wire from the starter solenoid, and verify With an ohm meter that the circuit continues on through the pull in coil to ground. I did not feel the need when I could make the starter work or not work simply by disconnecting/reconnecting the pull in coil.

I was surprised that the circuit works this way and that is why I included this detail in what I wrote above. I too am glad that with your help Dave the OP was able to get his tractor running again.

Edit: This is not meant to be a compliment. But I assume Dave is the same person as Dave_eng at the orange site. He is to be commended for his efforts to help so many people at both sites. Or if not the same person, both should be commended!