G1900 Problems Starting

dirtbiker · Oct 13, 2007

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 · Dec 8, 2007

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 · Jan 6, 2008

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 · Jan 13, 2008

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 · Jan 11, 2009

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 · Jan 8, 2010

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 · Jan 11, 2010

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.

jf080903 said:
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 · Oct 20, 2012

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 · Oct 21, 2012

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.