Mitsubishi S373D

[EBGwd]

Ahhh....
So the glow plug indicator is only in the circuit when you hold the key in heat position.
Thanks for the details and education. To be sure, if I put my switch in start the glow plugs will get warm but the indicator on the instrument panel will not be energized. So the glow indicator is just for the driver to observe. So, if I put the key in start but do not crank for 30 seconds, my glow plugs are heated in South Carolina anyway. Do I have it right, now? Thanks....

 

[Ilikeurtractor]

Just so we are using the same terminology, there are three key positions (technically 4 with off but I'll omit that here) on the Beaver III:

1.) Heat
2.) On
3.) Start

When the key is "on" no power is going to the glow plugs. The glow plugs have power going to them in the other two positions. You can't really have the key in the start position and not have the engine crank unless you pull the wire to the starter solenoid.

 

[carlbelson]

I thank you for having patients with as I am new at working on the computer .The trouble I am having is that I put in a aftermarket switch in my S373D Mitsubishi, I don't think I have it wired right .The way I had it, I turn the key to heat for 30 sec. then to start ,the motor starts I let go of the switch, it goes back to the on position the tractor stays running but the heat indicator on the dash stays red .this were I am not sure what to do. I tried switching the wire coming off the heat indicator an put it on with the wire to the stater .That did't work because when I turn it to heat the starter kicks in .So I unhooked that wire taped it up now the tractor starts and runs but I know that wire has to go somewhere.You can laugh if you want to because it is funny!As you can see I need a wiring diagram HELP

 

[Ilikeurtractor]

Is it a four-position switch (i.e. heat, off, on, start)? You'll need to diagram the connections on the switch for each key position with a continuity test (multi-meter) if they are not shown on the switch itself. Then you need the wiring diagram (attached) and you should be able to hook it up correctly. If you don't have a four-position switch that will create additional problems. I would recommend getting an OEM replacement switch from Valley Power if you can afford it.

Note: I just noticed the Satoh wiring diagram does not show the glow plugs wired off the "start" position (listed as connection "500") in the diagram even though this is how it is wired in reality. I actually found this out when tracing the wiring on the machine I restored. If you look at the Iseki wiring diagram, you'll see the glow plugs are fed off two independent wires which is correct. However, the Iseki uses a seperate key and start switch to accomplish this instead of the one the Satoh uses.

 

[carlbelson]

Thanks Ilikeurtractor I read your post downloaded the wire diagrams .The Isseki diagram looks about the same as the way my S373D is wired. But the glow plugs are wired different .Right now the tractor is running alright , I only have one wire hook up to the glow signal. I am going to look the diagram some more an try something else. Oh my the way my switch has 5 pins on it as did the one that was on it when I got the tractor .There was no paper work with the machine .I don't even know what hp it is ,only that it is a 3 cylinder diesel model S373D . That is why I am looking for some manuals for it.

 

[Ilikeurtractor]

If it's the stock engine it's a Mitsubishi K3A. Mine has a sticker that claims 16.5 hp on the machine but I have the power and torque curves for the K3A engine and according to those it's closer to 14 hp. I'm not sure if there were different versions of the engine that maybe have more power, but as you know in the tractor industry hp ratings are a big marketing item so there is every effort to make that seem as high as possible. The engine's "raw" hp may actually be 16.5, but it's net output I believe would be the 14 hp. There are also claims that one must consider "PTO" hp vs. engine hp, but since a lot of Mitsubishi engines went in different makes of tractors, I don't think the curves represent PTO power, but I could be mistaken.

I have a KE70 Mitsubishi engine in another tractor and there are references in different manuals that it has a power rating of 15 hp. All of the KE70 engines I've seen (and I haven't seen many) all have "13 PS" stamped in the block. A PS is equivalent to 735 watts - one U.S. hp is 746 watts. So 13 PS is slightly less than 13 hp.

In any case, these tractors have plenty of power for their size. I haven't found myself requiring more horsepower than they make. Sure there are lawn "tractors" that have 20+ hp out there but I doubt that gets used much, if ever. Also diesels tend to produce more torque at low rpms relative to gasoline engines and this makes them "feel" more powerful at slower engine speeds.