F24 Schematic Question

[Burt_Mitchell]

I bought one of the Yanmar operation manuals for my F24D from Hoye Tractor. The manual is really helpful. I've learned quite a bit from it.

However, if you are troubleshooting an electrical problem the schematics could be a bit better so I decided to redraw the schematic in the manual. Most of what they had sorta makes sense but there is one component in the schematics for every F series that is not labeled and I haven't been able to figure out what the silly thing is.

If you have that schematic it's the component below the horn, above the fuses and to the right of the regulator. It has one line that is always hot from the battery, another line that is switched by the ignition (main) switch and a ground line.

The only guess I've come up with is that is some type of cutout relay that disables something while the starter is cranking.

Does anybody have a better guess?

 

[Mickey_Fx]

Have noticed the same think on the schematics I have. I see this item on all schematics on the F17 and above models.

From what I see, there is a hot & ground wire and one going to the main switch. What I see missing is any reference to the valve that opens/closed the fuel supply to facilitate the main switch being able to shut down the engine.

From this quick look, my money is on fuel shut off valve.

 

[Burt_Mitchell]

I think I figured out what it must be. It must be the UFO module. I think I read that they were only on the F17 and higher models. That agrees exactly with the schematics. My UFO has three wires so that agrees too.

I wasn't aware that the engine had a fuel shut off solenoid. I'll have to look through the manual later and find out about that. I would think that it would be on all the engines, not just the F17 and higher.

When the weather is better I need to check out the labeling on the back of the main switch and light switch and fill them in. The labeling on the manual schematics is pretty much unreadable.

FYI I did find a couple problems with the schematics for the F24/FX24. They have the fuel sending unit hooked to the temperature gauge and vice versa. They also show a 15 amp fuse for the auxiliary power. It's really a 10 amp according to the cover on my fuse box.

If you want to see what I have so far you can download it from:
http://www.swproducts.biz/Downloads/Test/Yanmar_F24_Schematic.pdf
It's a lot more readable that what is in the manual.

When it's done I'll submit it to Murray Publishing so they can update the manuals. I still need to check the switch terminal labeling and fill in the semiconductor parts in the Warning Lamp Module.

 

[Tom_Veatch]

...
I wasn't aware that the engine had a fuel shut off solenoid. I'll have to look through the manual later and find out about that. I would think that it would be on all the engines, not just the F17 and higher.
...

There isn't one on my 2220D. Or if there is, it's not wired through the main switch. Fuel shutoff is a manual push-pull control on the center pedestal below the dash on the side opposite to the decompression control. I believe (and am open to being corrected) that most 4 digit models have an independent fuel shutoff either as a separate control or as an "idle shut off" position of the throttle lever.

More than once I've wondered why the fool thing wouldn't fire before noticing that I left the fuel shutoff pulled out after the last shutdown.

 

[Mickey_Fx]

If you shut your engine off via the key, you have to have an electrical shut-off valve. If the switch doesn't kill the engine then you have to do it manually as Tom stated.

Don't think the item you're talking about is the UFO controls. At least on mine, in addition to the joy-stick control there are 2 multi position switchs on the control panel and at least 3 sence/postion snap action switches on the 3pt hitch. That's a lot more electrical connections than 3.

Thanks for point out the error in the temp and fuel gages.

 

[normde2001]

Don't they use color-coded wiring on Fxx models?

 

[Burt_Mitchell]

When you look at the tractor it appears to be color coded. No mention of colors on the schematics.

 

[Burt_Mitchell]

If you shut your engine off via the key, you have to have an electrical shut-off valve. If the switch doesn't kill the engine then you have to do it manually as Tom stated.

Don't think the item you're talking about is the UFO controls. At least on mine, in addition to the joy-stick control there are 2 multi position switchs on the control panel and at least 3 sence/postion snap action switches on the 3pt hitch. That's a lot more electrical connections than 3.

Thanks for point out the error in the temp and fuel gages.

I think you must be right about the fuel solenoid. It's really the only thing that makes sense. I went through the manual again last evening. I didn't spot any mention of it.

There might not be as many external connections to the UFO as you think. If you look at the accelerometer/control unit as one unit, all you need is power, ground and two more wires to solenoids. If you're grounding through the chassis that means only three wires.

Even so, a fuel shutoff solenoid makes a lot more sense.

 

[Burt_Mitchell]

Another thought just occurred to me. Are there any electrical connections required for the shuttle shifter on the FX model? Those should be on the schematic too.

I have an F24D so I just don't know and I have no way to check.

 

[normde2001]

Don't they use color-coded wiring on Fxx models?

I forgot, those are not factory schematics. They tell the wire color.

 

[Mickey_Fx]

Burt, the shifter on mine is mechanical. As for the "unknown" componentent on the schematic being the UFO controls, it may only take 3 wires to power it but with the number of switches on the control box and the remote position switches, the item on the schematic should be showing a lot more electrical connections IF it was the UFO control. My money is still on the item on the schematic being the fuel shut-off valve.

There is no "thinking" about about the external conections for the UFO control. I know where at least 3 external switches are and know how they operate. You will find one that is actuated when the 3pt lift control is pulled ALL the way back. When actuated and the fwd mounted rotary switch on the UFO control is turned in the correct direction, the tilt on the 3pt will automatically level the right arm. There are 2 other switched mounted in a housing that spans the hyd cyl for the right 3pt arm. They tell the control when the cyl is at the correct extension to level the 3pt arms. I suspect the other rotary switch on the UFO control box is connected to the connector on the rear apron next to the right fender and connects to other components on a tiller. Have seen tillers with more controls than on mine and have seen one model with electrical shift to shuttle the tiller left/right. Yep, a lot more electrical connections needed for the UFO control.

I also suspect all the UFO controls for the tiller are included in the tiller manual and not in the tractor manual. The draft control on the tractor connects to the tiller machanically and I don't see anything in the tractor manual for that as well.

Lot of guessing and experimenting to find out how some of the controls work on the tractor.

 

[Burt_Mitchell]

I finally found a reference for the fuel solenoid in the operation manual. On page 19, section 12 it says that some models have an electrical fuel shutoff and some have a manual shutoff.

I had a couple spare minutes so I popped the covers on the tractor engine open. I was hoping I'd find the electrical connection right at the injection pump. No such luck.

 

[Mickey_Fx]

Here is a pic of my tractor. Shut-off is actually a motor and not a selenoid. THink the motor works a mech on/off valve. Located below the fuel filter and aft of the injection pump.

Sory for the focus but it was a little dark out at the barn.

 

[Burt_Mitchell]

I wondered if that might be the guy. The frame for my loader made it pretty hard to get a good look at it.

There must be some type of relay inside it too. Otherwise you wouldn't need the 12v wire from the battery along with a 12v line from the switch.

I've updated the schematic again if you want to take a look. I added a fusible link from the hot terminal of the starter to the main switch and regulator. There was a little squiggle on the Murray schematic that I missed before.