Kubota B7100 HST electrical issue

[Dbaker810]

It’s my first time on this forum.
I had a dead battery, so I replaced the battery. I probably cranked on it too long and saw a little bit of smoke come from the starter so I replace the starter. Now I get no power. The oil light used to come on when I turned the starter key now there’s nothing.
I replaced the starter ignition switch and still nothing. Multimeter says I have 12.56 V on the starter and the battery.
Fuses are good.
Any suggestions will help. Thanks

 

[85Hokie]

Wow !

O - and welcome to the forum!

Throwing parts somewhat blindly at the problem will break the bank!

There is a main fuse that you blew I am guessing. This B7100 is the old style - what I mean by that is it has a 4 bolt pattern on the front rim???

There is a fusible link near the starter - it looks like a "wire" - might be red in color - the wire is designed to melt.

But you say you have 12 volts at starter?

 

[mpsmdsr]

I have a similar issue with my M4900. One day the starter would not operate but lights came on strong. Since it is old, I had the starter rebuilt, but it does the same. when I turn the key off I hear a click then a delayed click. Since I don't have shop manual, I don't know whether there is a starter relay somewhere. Thanks in advance for any suggestions

 

[Dbaker810]

Wow !

O - and welcome to the forum!

Throwing parts somewhat blindly at the problem will break the bank!

There is a main fuse that you blew I am guessing. This B7100 is the old style - what I mean by that is it has a 4 bolt pattern on the front rim???

There is a fusible link near the starter - it looks like a "wire" - might be red in color - the wire is designed to melt.

But you say you have 12 volts at starter?

Wow !

O - and welcome to the forum!

Throwing parts somewhat blindly at the problem will break the bank!

There is a main fuse that you blew I am guessing. This B7100 is the old style - what I mean by that is it has a 4 bolt pattern on the front rim???

There is a fusible link near the starter - it looks like a "wire" - might be red in color - the wire is designed to melt.

But you say you have 12 volts at starter?

I do have an older style be 7100. I’m not really throwing money at it to fix problem. The battery would not hold a charge so it needed to be replaced. After I replaced the battery, it started up and ran for a few minutes. I drove around and it seemed to be fine. I tried to restart it and the solenoid would Whirl but it wouldn’t engage. That’s when I decided to replace the starter.
The fusible link on the starter you talked about, is it the small wire that clips on to the solenoid? It looks like that wire may have burnt a bit but it’s still in one piece.
When I put a multimeter on the solenoid, it shows 12.5.
I do know that when the key is turned it sends power to that clip on the solenoid which engages a starter.
Should I cut that clip off and get a new connector?

 

[North Idaho Wolfman]

Sounds like the smoke was from the main fuse just above the starter.

Jump from the large battery terminal on the starter to the solenoid terminal, does it crank?

 

[GreensvilleJay]

The smoke could also be coming from old, corroded battery cables.
While a meter can say '12 volts' at the starter, there's not any CURRENT available.
If you put a good battery on the ground, connect jumper cables AT THE STARTER, engine may start fine. If so for sure the tractor's battery cables need to be replaced.
It only takes a few drops of water to start copper wire to corrode..from the inside out.

 

[Russell King]

It’s my first time on this forum.
I had a dead battery, so I replaced the battery. I probably cranked on it too long and saw a little bit of smoke come from the starter so I replace the starter. Now I get no power. The oil light used to come on when I turned the starter key now there’s nothing.
I replaced the starter ignition switch and still nothing. Multimeter says I have 12.56 V on the starter and the battery.
Fuses are good.
Any suggestions will help. Thanks

There is probably a blown fuse or the main fusible link has failed. But some of what you say is a little misleading. I assume you mean you have the 12.5 volts on the large battery cable that connects the battery to the starter. But do you have any voltage on the wire from the key switch to the solenoid when key is in start position?

If you can’t figure it out I would be willing to look at it for you since I am in Austin also. If you want me to help you can send a private message by tapping on my name

 

[Russell King]

There is a electrical schematic for your tractor in the first post of this thread

Electrical - Wiring Diagrams

"Diagrams may vary depending on the Exact model, serial number, region and options equipped" Hopefully those looking for an electrical-wiring diagrams for a given tractor can find them here. Those that are willing to share, please make the POST TITLE that starts with the tractor specific...

www.orangetractortalks.com

Since you asked in your PM about how to test the voltage to the solenoid…
On the left side of the schematic is a SAFETY switch, the key switch is shown above and the starter below the safety switch. The wire running from the key switch (#50 terminal) to the safety switch and to the starter is described with AV2 BaW is what will provide 12 volts to the solenoid. But the safety switch has to be depressed by the clutch pedal being pushed down. That wire is black with a white stripe.

I assume you know how to use a voltmeter but will provide some guidance for those that need it. Attach the negative and positive leads to the voltage meter and set it for DC voltage above 12 probably like 20 volts. Test the meter by touching the test leads to the battery terminals and it should show around 12 volts.

Now move to the starter area of the tractor and attach the negative lead of the meter to ground and the positive lead to the battery cable attached to the starter. Again the meter should read the same as before at the battery (12 volts).

Now to test the solenoid wire voltage take the black wire with white stripe off of the solenoid and attach the volt meter positive lead to the wire terminal. Have a helper turn the key on, push the clutch pedal down and turn the key to the start position and hold it. The volt meter should read 12 volts if everything works properly.

If the meter shows no voltage then you can move to the safety switch and see if the wire going to either side of the switch has 12 volts with the key in the start position. If yes then you would know the switch was bad and replace it.

If no voltage is found then move to the key switch and see if there is voltage on terminal 30 and if so then move to terminal 50 and hold the key in the crank position.

I think you should really just start with seeing if there is power on terminal 30 of the key switch since you don’t seem to have any power to the dash (alternator) light.

I think you may have a problem with the RED wire from the starter to the key switch. If you can see where you have 12 volts at the starter and along that red wire.

 

[Dbaker810]

There is a electrical schematic for your tractor in the first post of this thread

Electrical - Wiring Diagrams

"Diagrams may vary depending on the Exact model, serial number, region and options equipped" Hopefully those looking for an electrical-wiring diagrams for a given tractor can find them here. Those that are willing to share, please make the POST TITLE that starts with the tractor specific...

www.orangetractortalks.com

Since you asked in your PM about how to test the voltage to the solenoid…
On the left side of the schematic is a SAFETY switch, the key switch is shown above and the starter below the safety switch. The wire running from the key switch (#50 terminal) to the safety switch and to the starter is described with AV2 BaW is what will provide 12 volts to the solenoid. But the safety switch has to be depressed by the clutch pedal being pushed down. That wire is black with a white stripe.

I assume you know how to use a voltmeter but will provide some guidance for those that need it. Attach the negative and positive leads to the voltage meter and set it for DC voltage above 12 probably like 20 volts. Test the meter by touching the test leads to the battery terminals and it should show around 12 volts.

Now move to the starter area of the tractor and attach the negative lead of the meter to ground and the positive lead to the battery cable attached to the starter. Again the meter should read the same as before at the battery (12 volts).

Now to test the solenoid wire voltage take the black wire with white stripe off of the solenoid and attach the volt meter positive lead to the wire terminal. Have a helper turn the key on, push the clutch pedal down and turn the key to the start position and hold it. The volt meter should read 12 volts if everything works properly.

If the meter shows no voltage then you can move to the safety switch and see if the wire going to either side of the switch has 12 volts with the key in the start position. If yes then you would know the switch was bad and replace it.

If no voltage is found then move to the key switch and see if there is voltage on terminal 30 and if so then move to terminal 50 and hold the key in the crank position.

I think you should really just start with seeing if there is power on terminal 30 of the key switch since you don’t seem to have any power to the dash (alternator) light.

I think you may have a problem with the RED wire from the starter to the key switch. If you can see where you have 12 volts at the starter and along that red wire.

Thanks Russell,
I checked the battery terminals and the battery reads 12.5 V.
Connecting a meter to the starter and it reads the same as battery. Removing the black and white wire connection from the solenoid I checked it with the clutch pressed and the ignition switch on. It read the same 12.5 V. Releasing the ignition switch the voltage drops.
Checking the voltage on the ignition starter switch reads the same as a battery when the ignition is turned on.
Checked all the fuses they all seem good. I still don’t get an oil light on the dash.
This is an old tractor, so nothing electrical worked except the oil light, glow plug indicator and ignition switch.
When I jump the solenoid main red wire to where the black-and-white wire connects to the solenoid, the motor will try to turn over.
I’m stumped!! More of your advice is greatly welcomed.

 

[North Idaho Wolfman]

Have you verified the polarity?
I've seen several times where people hooked it up backwards.
When you jump the solenoid on the starter it should start and run there is nothing electrical that stops it from running.
There are several glass fuses under the dash that could effect the lights.

 

[Dbaker810]

Have you verified the polarity?
I've seen several times where people hooked it up backwards.
When you jump the solenoid on the starter it should start and run there is nothing electrical that stops it from running.
There are several glass fuses under the dash that could effect the lights.

Yes I have verified the polarity on the battery is correct. There are only three fuses that I can find and they all checkout okay. Is there one fuse that controls the starter I guess the fuse holder could be bad. The lights on the tractor didn’t work when I bought it.
There is no fusible link on the starter.

 

[North Idaho Wolfman]

The fusible link is in the feed wire from the starter to the ignition switch.
It will be located above the starter.
No fuse controls the start function. on that model the signal starts at the switch goes through the clutch switch to the starter.
Doesn't really get much simpler than that.
If your not getting dash lights, glow plugs, or start signal, then your very likely to have burnt the fuse link or the main wire to the switch or the switch itself.
Really easy to follow with a simple test light.

 

[Russell King]

Thanks Russell,
I checked the battery terminals and the battery reads 12.5 V.
Connecting a meter to the starter and it reads the same as battery. Removing the black and white wire connection from the solenoid I checked it with the clutch pressed and the ignition switch on. It read the same 12.5 V. Releasing the ignition switch the voltage drops.
Checking the voltage on the ignition starter switch reads the same as a battery when the ignition is turned on.
Checked all the fuses they all seem good. I still don’t get an oil light on the dash.
This is an old tractor, so nothing electrical worked except the oil light, glow plug indicator and ignition switch.
When I jump the solenoid main red wire to where the black-and-white wire connects to the solenoid, the motor will try to turn over.
I’m stumped!! More of your advice is greatly welcomed.

Well that is somewhat good but surprising information. It also proves that you have the skills needed to resolve this yourself!

When you jumped the battery cable terminal to the solenoid it was just supplying 12.5 volts to the solenoid which is the same as the solenoid wire voltage. Not knowing how you jumpered it I have to assume you used a screwdriver or a heavy wire which could carry more amperage than the black/white wire can. But the solenoid shouldn’t take too much amperage to work.

Also please be more clear with the results. When you state “will try to turn over” that leaves a lot to interpretation. Did the starter chatter, did it actually spin the motor at a slow or normal speed. If the starter was spinning the motor at normal speed did the engine try to start? Did you just stop trying to get it started since your end goal is to get it cranking from the seat with the key?

So please be a bit specific about the results since it might provide some insight into the problem.

For the oil light you can check out the bulb or replace it. On my L185 they were strange small bulbs that the dealer had to get. I don’t think you could find out if the bulb holder has voltage due to the size but you can evaluate if there is enough room to get the probes of your meter.

Take notes as you go along so you can remember what happened in each case.

Here is how I would proceed (normally):
1) evaluate the battery (yours is brand new so we can assume it is good for now)
2) evaluate the battery cables and the connections. I tend towards replacing battery cables if they are old and suspect but just make sure the cables are sufficient size, ends are well connected to the cable and all four connections are clean and tight. The cables are probably a huge issue in many situations like you have.
3) Evaluate the starter (yours is new so we can assume it is good for now)
4) Clean the mounting surface where the starter mounts to the engine.
5) Evaluate the key switch power (done and good). You may want to clean every wire terminal with Emory cloth as you go through this.
6) Evaluate the voltage at the end of the black/white solenoid wire. (Done and good)

So really your tractor should be cranking from the key as normal!

But since it’s not cranking we have to go further. But please review the steps above and take care of the cables and things that you have not already covered yet.

After you are sure about everything above and if the tractor is not spinning the engine.
1) Take jumper cables from your battery to a known good battery if you can easily. Try to start tractor.
2) take the jumper cables and connect the tractor positive battery terminal to the starter and negative jumper cable to the starter mounting bolt. Try to start the tractor.
3) now take the jumper cables off the tractor battery and put them on the known good battery. Try to crank the tractor.
4) Take the jumper cables off and take a large wire (14 gauge?) and attach one end to the positive battery terminal and touch the other end to the solenoid spade terminal.

That is about all the trouble shooting steps to isolate where the problem is. You should be able to isolate what wires or connections are limiting the power to the solenoid or the starter.

If you need to use the tractor you should be able to use the glow plugs and jumper the starter and get the tractor to start. The key has to be in the run position of course before jumping the starter.

 

[Vigo]

Starter needs two powers and a ground to function.

Power on big wire (constant, it's directly connected to battery positive terminal)
Power on small wire (only when key is in crank position and clutch pedal is pushed)
Ground (starter grounds through its housing, through engine, through bellhousing, over to wherever the main ground wire from the battery is bolted down, mine are on steering gearbox, yours may be somewhere slightly different).

Logic statements:
IF you jump power to the 'small wire terminal' on the starter and the starter successfully turns the engine at normal speed, THEN: A. Battery is sufficient. B. Voltage drop on power and ground sides of starter circuit are acceptable. C. Starter itself is functional.

IF starter functions in the scenario above, and you HAVE 12v on your small wire when it is disconnected from the starter, but when you reconnect it to the starter it still does not crank, THEN you have a big voltage drop on the 'small wire circuit', which probably comes down to a bad connection either at the ignition switch or the clutch pedal switch.