B series electrical question

[richie]

Greetings! This is my first time posting o this forum, so I will give a quick introduction. I picked up a B6000 Kubota tractor a couple of years ago for what I thought was quite cheap (under $500.00 + a small trade). It was my first Kubota and it has been a good tractor for me. Needs a little body work, but thats what winter is for!

My question is there is a small red light above the key on the tractor that I always thought was an ignition light or something, but from what I see in the service manual wiring diagram, it shows it to be an oil switch light. The service manual does not show any ignition light. Is having the light on when I turn the key on good or bad? Perhaps someone tampered with the wiring? Any answer would be most appreciated.

 

[Stumpy]

That light should indicate whether the engine has oil pressure or not. It's a simple pressure switch. It should come on when the key on and the engine isn't running and shut off a few seconds after startup. If it remains on after startup either the switch is faulty or you've got an oil pressure problem. Don't run the machine if the light stays on after startup, an engine without oil pressure will self destruct fairly quickly.

 

[richie]

As far as I can remember, the light does stay on after start up. But I have never had any problems with the oil and it seem to run good. I have ran it this way for three years and no problems So I'm guessing it is a faulty switch like you said. After all the tractor is quite old Would there be any reason that the oil pressure would not build?

 

[seanbarr]

Just about all oil pressure switches are grounding types when there's no pressure. When sufficient pressure builds up, the switch will break contact with ground, thereby signifying "all clear". If you're still seeing the light, there's insufficient oil pressure or the switch is bad. Possible to have both!

 

[murky]

A new switch is about $15 and takes 20-30 minutes to install.

 

[phildac]

A new switch is about $15 and takes 20-30 minutes to install.

I agree, replace the switch!

 

[Stubbyie]

If problem persists, question(s) arise, or you just want to be certain what the lamp is or is not telling you, consider installing a test gauge into the port where the electrical sensor is now installed.

You can have both lamp and gauge by using a tee fitting and appropriate plumbing.

BE AWARE the threads are NOT "normal" U.S.-type bolt or pipe threads. May be metric but much more likely to be "British". My aplogies, I've just forgotten the nomenclature for those durn threads. You'll need a cross-over aka adapter. Some on here have advocated using a guage with its nipple wrapped thick with teflon tape or simply screwing in whatever almost fits. May work, but you run the very real risk of ruining the threads in the head. Then life gets interesting, fast. Wait a minute, BST is "British Standard [Pipe] Thread. Adapters may be available at large auto parts houses. Unless you have a female thread gauge you might have to "feel" your way along by trying a couple different sizes.

 

[richie]

I will probably just replace the switch. I am doing some other stuff to the tractor right now so I can't run it anyways. I hope that works, I really don't know why it wouldn't. Does anyone have any reasons why there would not be good oil pressure other then a leak? Thanks for all your help!

richie

 

[Stumpy]

There are little plugs pressed into the drillings for the oil passages in the valve cam shaft that can pop out. That's one possibility nut there are a ton of others. Clogged filter screen, failed oring somewhere in the oiling system, relief valve stuck open... Hope the switch does the trick! Stubbie is right by the way, they are BST threads that look very close to standard NPT pipe threads but won't seal properly. You can order adapters from Summit Racing, Autometer makes them. I'm just using a generic pressure switch with an adapter myself.

 

[Kubota_Bob]

First things first..........

To troubleshoot the problem the first thing is to unplug the wire to the sender to see if the light turns off...........if the light doesn't turn off there is a problem with the wire between the sender and the light....the problem would be that the wire got pinched and is now grounded.....if the light goes out you can move on to the next step....

Next screw in a pressure gauge and see if in fact the engine has oil pressure..

If the engine has pressure and the light goes out when the lead is unplugged than you know for sure that the sender is defective.....

Thanks to all of the members of this forum that have supplied me with information,

Bob

PS........I just purchased a B7200DT with FEL, backhoe, blade box, auger and rototiller from a friend of mine and I will pick it up next week..... Again the info that I learned here helped me buy my first tractor!!!!!

 

[richie]

Thanks for your advice Bob! Like I said I will not get a chance to test it for awhile. I am going to replace all the wiring on the tractor anyway. I'm guessing that it is either a faulty switch or faulty wiring or both! BTW congratulations on your new orange purchase!

richie