G1900 Problems Starting

[dirtbiker]

Hello,
New to the group and first time posting. After lots of research, I just bought myself a used G1900 (with only 50 hours on it). It's a 4WS with a 60" deck. I cut my 1.5 acres with it first time last night and what a treat!

The problem that I'm having is with initial start. With the brake pedal depressed and key in the glow position, I wait until the glow indicator goes out and then go to engage the starter...nothing! The guy that I bought it from says that I'm not holding the key deep enough into the glow position, but I don't think that's the case. After 10-15 attempts, bingo it fires right up. Just to be sure that I'm explaining myself correctly, the attempted starts result in nothing (no starter engagement); however when it cranks it fires off immediately.

What I did notice is that when it WILL start, I hear a click like a relay closing. Has anyone experienced this issue or have some ideas of things to check first? Many thanks in advance!

Jim

 

[milkman]

Sounds to me like low battery voltage, either low battery or loose or dirty connections. After you use the glow plugs, seems that after it sets a little the battery rebounds enough to crank, if I read your post right.

 

[art]

I always start with clean terminals first, it doesn't cost much to scrub them up with a little sand paper if nothing else is available.

The second step is to hold the key on and then keep repressing the brake petal to see if that switch is working as well as the pto until it might crank.

 

[cityfarma]

The general theory is that the starter should always try to start even without using the glow plugs. The glow plugs make it easier to fire but should not effect the actual starting motor.

When you switch to start, a relay on the starter should operate and switch the battery to the motor windings and the motor should start to spin.

Get a meter and check that the starter solenoid (relay) is getting 12 volts on the switched terminal (the lighter gauge wire) when you try to start. If no 12v, you can get a wire straight from the battery to the terminal to check if the motor starts. THIS IS VERY DANGEROUS!! BEST DONE WITH ONE PERSON ON SEAT WITH CLUTCH AND BRAKE PRESSED!! If motor turns over, wiring confirmed faulty.

If there is 12v on the terminal then you probably have a solenoid/starter problem.

If there is no clicking when you try to start, it suggests that the solenoid is either not getting 12v or is not operating. Check that the contacts on the terminal are clean.

If low voltage (<12v) on the terminal then check the battery.

Cityfarma

 

[dirtbiker]

Thanks for the feedback everyone. Battery voltage is not the problem. Something is preventing the proper signal from reaching the pull-in winding on the starter solenoid. I do have one clue: If I move the hydrostat pedal around a bit before attempting to start, it fires right off. Is there some sort of a safety or interlock on the hydrostat? Does anyone know if that's been a problem or not on this model?

Thanks Again!
Jim

 

[cityfarma]

I would guess that there is an interlock to prevent the engine starting with the pedal pressed. That would be the equivalent of starting in gear. Check if there is a switch actuated by the pedal.

Cityfarma

 

[ensign]

Did you ever get this problem resolved? Did I just buy your tractor? I'm having the same type of problem on my G1900S. Sometimes it starts fine, other times, the dash lights won't even come on. Jiggling the wires under the steering wheel can get the lights to come on, but doesn't start it. Can't figure out what triggers the starting sometimes.

 

[ensign]

My buddy and I started troubleshooting last night and we came across a wire that had broken free from the harness plug. We will be performing surgery as soon as possible. Hopefully, this will resolve the starting issues.

 

[Volfandt]

A broken wire will do it every time

Keep us posted on your fix, it'll no doubt help others on down the line.
Don't see why the G series can't be benefitial here anyways

Good luck on the impending surgury....

 

[ensign]

Ok, the broken wire got the dash lights to come on, but it still wouldn't start up. We started troubleshooting all the safety switches. Found that the brake pedal switch seemed to be a little flaky. Turns out when the brake is on, the button is out on the switch. If you move the button in just a little bit, it will start right up. Will try to find a new switch, but at least I can get it started without any problems now.

Whew hoo!

 

[dirtbiker]

Hello Group,
Very sorry for not posting my fix for the starting problem that initiated this thread. As I had mentioned in my first post, the tractor wouldn't crank at all (intermittantly), but when it did all was fine. This pretty much ruled out a bad battery, voltage drop and so forth. The fix was a total "by accident." It turns out that if I jiggle the hydrostatic control pedal prior to starting that it would start consistently. There must be a switch on the pedal assembly that interrupts crankings if it senses a depressed pedal. This switch must be a bit sticky. (I'm not surprised as it had 40 total hours on it when I bought it and it's what...12 years old).

Thanks,
Jim

 

[dirtbiker]

Ensign,
It certainly sounds as though you've run into the exact same problem that I'm having. My G1900 has been parked in the garage since "converting" it over to winter operation (guy I bought it from threw in 42" blower and suitcase weight kit). I figured that I should keep the battery charged so I went out last pm to start it up...same deal...lights on - nobody home! I played with the brake pedal and it started perfectly.

I don't have a book on the machine yet. Could someone tell me where the brake interlock switch is located? Maybe a shot of WD-40 or the like?

Thanks All!
Jim

 

[smseely]

I am having the same problem with my G6200H. It used to be, "Jiggle the pto or push in the brake and whammo, cranks right up." Starter was clicking, then nothing. Just replaced the solenoid and a fuse. Still nothing. Probably a safety switch. Getting ready to have battery tested and put the meter on to see if getting 12v at the solenoid. New battery since 4/07 with 435ca and 520cca. Will keep you posted, let me know if your bad wire was the case.

 

[smseely]

Found pto safety switch was bent and not making contact. $1 spring/$82 labor. Spent 1 1/2 hours looking for the problem with the tractor mechanic.

 

[txcactusdude]

Well my G1900S was experiencing the same problem, intermittent starting. It was driving me crazy not knowing if the tractor would start or not.

I traced it to the brake interlock switch on the brake peddle.

It sure looked as though it was extending all the way out, but with just a little nudge it came out enough to make the contact. There sure isn't much distance from good to no contact.

I took the switch off and removed the boot. I then sprayed some lubricant on the plunger and it seems to be working. The tractor started a number of times without incident.

I had started with the battery grounding and then went to the starter. When I jumped the contacts on the starter it turned over so this indicated the starter solenoid was OK. This led me to start looking at the interconnects on the PTO and brake.

Hopefully I can get on and mow now without worrying about if it will start.

 

[jf080903]

here's the problem there is a safety switch under the tractor that is hooked to the brake pedal, push the brake pedal and see if the plunger moves if not the cheap fix is snip the wires going to the safety switch and crimp them together with a connector. I also eliminated the seat switch and the PTO switch.

 

[ensign]

I thought I had replied, but after reviewing the thread, I see that I forgot. I did end up getting a new switch (the one you mention below) and that took care of the problem.

I'd probably be reluctant to bypass all the safety switches, but I guess that takes care of it too.

Thanks.

here's the problem there is a safety switch under the tractor that is hooked to the brake pedal, push the brake pedal and see if the plunger moves if not the cheap fix is snip the wires going to the safety switch and crimp them together with a connector. I also eliminated the seat switch and the PTO switch.

 

[tinab]

I bought a used Kubota G1900S this summer, and it has frequent non starting issues, I can start it by wire jumping the solenoid, so what does that tell me might be wrong?
I put a jumper wire in the seat safety switch, that did not work, I tried a relay switch to the solenoid, that did not work, and I can not find where the other two safety switches are. Does anyone have an idea?
I have only gotten to use the machine less than 8 times, at least now I can get it started thanks to Ed... but i would like to figure out what is actually wrong.
Thanks for any help you may have.
Tina

 

[jinman]

Tina, I've seen this problem reported many times on this forum. I had a similar issue with my G1800 and found the ignition switch was the culprit. For some reason, these switches seem to get dirty contacts and drop more voltage than they should. I measured the input voltage to my switch and it remained constant. However with a voltmeter measuring the "start" signal from the switch, I found it to be 10.5 volts out. Because the switch is in series with the starter solenoid, that lower voltage (and lower current) is not enough to make the solenoid engage. I could do repeated attempts at turning the switch to "start" and it might have a different reading each time. Anytime the voltage went over 11 volts, that was enough to engage the solenoid and the starter worked. Like you, a hot-wire jumper at the starter worked perfectly.

I know I could probably have replaced the switch, but it irritated me that the switch failed like this. What I did was to install a momentary contact switch (cost $9) with wires going to the starter. Essentially, the switch is a hotwire jump between the hot terminal on the battery and the solenoid coil wire that only makes contact when I press it. A link to the schematic and photo of my installation is here. I suggest reading the whole thread also.

I understand that everyone doesn't want to make a modification like this. You may not feel confident enough to do this kind of electrical work either. If not, I just think you'll have no other choice but to replace the starter switch. Here is a link to the ignition switch for the G1800. I suspect yours is the same or similar and the price will be very close to this. $52 is not a bad price, but of course, installation is the hard part.

Understand that without making measurements on your G1900, there is no way I can be sure. This is just a SWAG by someone who experienced identical symptoms. Your problem could be in the Combination Box also. If so, be prepared for a part cost around $250. Kubota thinks a lot of that part.