Frustrating Kubota Starter Problems

[Spaceman]

I have a 95 Kubota B2100HST. I am having some very frustrating starter problems. Last summer (2009) the starter started clicking, that is not engaging with the flywheel. Not all the time, just periodically until November when it did it all too frequently. I initially replaced the key switch because I was getting 7.3v at the solenoid and the battery was at 12.3v. This didn稚 cure the problem and I found the battery was 14 years old and replaced it. This did the trick until Last April (2010) when it started again. I had the battery tested and it had full power.
I finally brought the starter to be rebuilt last week because I could hardly start the tractor anymore. Guess what? It still did not engage! The technician told me he replaced the solenoid, brushes and bushings. I知 still getting a voltage drop to just over 7v at the solenoid. I致e checked all the wiring from the key switch, the main battery cable and nothing indicates anything over 0.2 ohms. There is full battery voltage to the key switch and the starter motor, the injectors are reading the proper resistance, I致e cleaned the battery terminals, and the where the ground attaches on the chassis. I致e jumpered out the safety switches to see if they were a problem. Nothing works. However, if I cross the starter terminal directly to the solenoid with a screwdriver, it works every time.
I am at my wits end. My only possible answer next is, is the correct starter in there? It has a Mitsubishi label on it. Is it possible the previous owner put a substitute in? What in the world is happening here?

 

[MikeInEburg]

I have a 95 Kubota B2100HST. I知 still getting a voltage drop to just over 7v at the solenoid.

If starter works every time with screwdriver shorting, then it's generally not the starter. I'm thinking that it's the soleniod. If only 7v when you're NOT turning the key (on the battery side of solenoid) then you have a bad connection somewhere.
Mike

 

[Spaceman]

The solenoid was supposably replaced when the restarter was rebuilt last week. I'm getting the 7v at the solenoid when the key is turned to start. Sorry if I wasn't clear on that. Thanks for your help.

 

[MikeInEburg]

What do you get when the key isn't turned to start? Again, if jumpering the solenoid works every time, it points to the solenoid as the culprit...

 

[Gator6x4]

Cub Cadets are famous for the no start "Click". You are not getting 12 volts to the starter solenoid. You need a wiring diagram to determine if the start circuit has a "Relay" built in. If the the starter circuit does not have a relay built in add one and your problem will disappear. Do a search in the Cub Cadet forum and you will find tons of information.

 

[J_J]

If you can take a heavy wire and go from battery to the start terminal of the solenoid, then the voltage level is being dropped before the solenoid. If the solenoid just clicks when you turn the key, then the voltage is being lost, probably in a relay contact, or loose connection, or a wire is frayed and is only using only a couple of strands for the current.

Check the voltage at each junction from the battery to the start terminal.

Replace the relay, and check wire ends and terminals, and or fuse housing for corrosion, etc.

Are you getting 7 volts before the starter is even turning. That is definitely not right. It would be normal to read this level as the starter is drawing current.

 

[Spaceman]

The wire from the key switch runs to the solenoid with 3 safety switches in between. It is only active when the switch is turned to start. I've jumpered out all the safety switches to see if there was a problem, but no change. The resistance from the switch to the solenoid is .2 ohms, and that is the same of the leads on the multimeter. I also checked for a short to ground and none exists

While the voltage drops to 7.3v when the switch turns to start, it returns to battery voltage when if I disconnect the solenoid.

I just had it rebuilt, and the technician said he replaced the solenoid, bushings and brushes. Unless the new solenoid is bad (or the place ripped me off and never replaced the solenoid), or the starter is not original equipment or replacement, I have to suspect the previous owner put in the wrong replacement.

There are only 700hrs on the tractor now. I can't imagine it already had a starter replacement before I bought it at 570hrs. It is a Mitsubishi starter, and all the replacement parts I've bought in the past say Kubota on them.

I'm considering buying a 6v relay and using it to activate the solenoid with 12v from the battery cable on the starter. Don't want to screw anything up as this is my favorite toy.

 

[J_J]

Did you Turn the switch, and touch the start terminal with 12 directly from the battery? If the solenoid and starter are good, the engine will turn over. If not, try a battery jumper cable and touch the starter B+ terminal. If the solenoid is built on to the starter, you might not be able to do this. Somewhere in those safety switches, you are losing voltage. When you take a starter to a starter shop, he will put 12v directly to the starter and see if it turns.

 

[Willl]

voltage drops to 7.3v

I'd bet 2 bits you have a connection problem. Or a bum batt.

With your volt meter, start at the battery 'posts' and work your way down to your voltage loss.

 

[Gator6x4]

Go here and head all the post and see if anything sounds like the problem you are having.

http://www.tractorbynet.com/forums/cub-cadet/111040-7xxx-series-starter-problem-again.html

 

[kebo]

Yep, it sure sounds like you have the same problem I had on my JD 750. A guy at a starter shop had seen it many times before and helped me fix the problem: When I turned the keyswitch, it would click, but not spin the motor over. Here's a clue to see if you have the same problem... turn the key switch over until you hear the solenoid click, then take a soft mallet hammer and hit the starter sharply with it a couple times (If that doesn't work get a regular hammer but don't break the casting!). If it magically engages and spins the motor over, then you will need to add the extra relay.

John Deere actually has a kit for this, don't know about Kubota. The relay basically jumpers over the heavy 12V starting current to the solenoid so it will "kick" a little harder when it engages. The voltage you measure on the starter and solenoid may be ok, but there is enough wiring/connection resistance throughout the entire circuit to limit the current getting to the solenoid. Even if the extra relay doesn't entirely solve the problem, it will help it work better especially on the cold mornings.

 

[wushaw]

Volt meter on battery, key in start position...what voltage are you reading?
Volt meter on starter (large) battery cable, key in start position...what voltage are you reading?

Also clean all your frame grounds & battery terminals, don't just look at em take a wire brush to em and make em shine.

 

[Treemonkey1000]

I am with JJ and his answers. If it is dropping to 7 volts with all of the current you are trying to pull it can be solenoid or connections. Relays get burned and pitted contacts will drop a lot of voltage with just a little pitting. Take off the battery terminals and cables. Look for oxidation. Brush up ground cables with a wire brush. Rusted ground bolts and also the positive terminals will mess you up. I have had starters and solenoids rebuilt and still fail. So it could still be bad. First thing to start with is take a look at the high current connections very closely....

 

[banjodunn]

G'day frustrating things these elec dramas :confused2: grab a set of booster cables and go from the neg side of the batt to the body of the starter that will isolate the ground circiut to the starter at least if you still have low voltage then try the same with the pos side , if this still does no good then jump from a good battery with the other vehicle running. One of these should give you 12 volts at the starter and should help you track down the prob


Jon

 

[J_J]

He has already proven that the starter works. The problem is the relay does not have enough voltage to pull in the relay, or the disc in the relay is severely corroded or pitted. If you ever take a bad one apart, you can see what could happen. Years ago, we would just clean the copper ring, turn it around, and re-install. I can almost bet that if he puts one of those thumb starter switches on the relay start terminal, it will start every time. He is doing the same thing with the screw driver.

 

[RickB]

I would introduce 12V to the start terminal on the solenoid (directly from the battery) and see if it closes and cranks the engine. I think that is the same thing J_J is suggesting. The solenoid coil will not close with 7v. Does the positive battery cable maintain battery voltage at the solenoid end while the control circuit drops to 7v?

 

[Gator6x4]

The man at the starter rebuild shop is probably correct, the starter and solenoid is good. The poster has already stated he can use a screwdriver and jump across the terminals and the tractor will start, so the starter and the solenoid is working. What is not being supplied is the 12volts to the solenoid. Remember where the poster said he was recording 7.2 volts at the solenoid when the switch was turned to the start position. To effect a fix, Purchase a five (5) spade terminal relay. I like the type with a tab. This allows the placement of the relay near the starter with a sheet metal screw. Some like the type that mounts through the use of a bracket. The relay needs to have the following terminals, 30-85-86-87-87a. A auto parts store can supply. Or, if you want to spend big bucks purchase one from MTD/Cub Cadet. The part # for the Cub Cadet relay is 925-1375.
Remove the wire from the key switch to the starter solenoid. (Remove the wire at the solenoid - pull from the spade terminal)If you are lucky, install this wire on terminal # 85 on the relay. If unlucky splice a wire onto the wire so it will reach where you have mounted the relay. Connect a wire to terminal # 86 and attach the other end of the wire to a good ground. Install a wire on the terminal on the starter where you previously removed the wire from the switch, attach the other end of the wire to terminal # 30 on the relay. Install a wire with a 20 amp inline fuse on the main battery wire at the starteer or another 12 volt source. Connect the other end of this new 12 volt source to terminal # 87 on the relay. No wires should be connected to terminal # 87a. Now when you turn the key to start, the voltage from the switch collapses the relay and the new 12 volt source engerizes the starter. This no start or clicking problem started when safety switches where added to the start system. If a fix is not desired we can continue the discussion.

 

[RickB]

The man at the starter rebuild shop is probably correct, the starter and solenoid is good. The poster has already stated he can use a screwdriver and jump across the terminals and the tractor will start, so the starter and the solenoid is working. What is not being supplied is the 12volts to the solenoid. Remember where the poster said he was recording 7.2 volts at the solenoid when the switch was turned to the start position. To effect a fix, Purchase a five (5) spade terminal relay. I like the type with a tab. This allows the placement of the relay near the starter with a sheet metal screw. Some like the type that mounts through the use of a bracket. The relay needs to have the following terminals, 30-85-86-87-87a. A auto parts store can supply. Or, if you want to spend big bucks purchase one from MTD/Cub Cadet. The part # for the Cub Cadet relay is 925-1375.
Remove the wire from the key switch to the starter solenoid. (Remove the wire at the solenoid - pull from the spade terminal)If you are lucky, install this wire on terminal # 85 on the relay. If unlucky splice a wire onto the wire so it will reach where you have mounted the relay. Connect a wire to terminal # 86 and attach the other end of the wire to a good ground. Install a wire on the terminal on the starter where you previously removed the wire from the switch, attach the other end of the wire to terminal # 30 on the relay. Install a wire with a 20 amp inline fuse on the main battery wire at the starteer or another 12 volt source. Connect the other end of this new 12 volt source to terminal # 87 on the relay. No wires should be connected to terminal # 87a. Now when you turn the key to start, the voltage from the switch collapses the relay and the new 12 volt source engerizes the starter. This no start or clicking problem started when safety switches where added to the start system. If a fix is not desired we can continue the discussion.

I'm not disagreeing with you. But that particular problem should and can be positively identified prior to purchasing & installing an additional relay. Reason being, there are other possible causes for the OP's symptoms, ie; a bad solenoid. .

 

[Chilly807]

When under load, as in cranking, the battery voltage will drop off to maybe 9-10 volts at worst in my experience.

If you're only getting 7 volts to the solenoid, it won't engage the main contacts and spin the starter. I'd say you need at least 8-9 volts for that.

If there is a relay in the circuit, which there usually is to save the key switch contacts, it's probably the culprit. If there isn't, the winding in the solenoid may be shorted, which will drag the voltage down. You can test that by checking continuity from the key switch lug to the starter case, it should be infinity.

Any continuity or resistance tests should really be done with the wiring disconnected. We already know there's a problem somewhere, so assuming a circuit is open can lead to false results.

If the starter works every time you jump the solenoid, and it started the tractor up to this point, I'd say you can rule it out. Also your main ground is fine, or else it wouldn't start, period.

You're going to have to remove the wiring from the starter and "start" (sorry about that, can't help myself) working your way back.

I think what's wrong is pretty simple, just a matter of isolating it.

Sean

 

[d1king]

Had similar problem with older b2400. Dealer wanted app $600 for wiring, switch, starter etc. several years ago. Turns out this is common concern, caused by cumulative voltage drop to solinoid as circuits age. Installed J.D. part no am107421, I, like several others, have had no further problems. Try a search for 'b2400 no crank', start with victor43 thread of 8/19/04 and follow thru. Has wiring tips, can also use low voltage automotive relay. I liked the J.D. relay because it went on so quick and neat. Good Luck