G1900 Help - Won't Start - Did all that I have read to troubleshoot without success

[wadeal]

I have been using this site for years .. thanks in advance for the indirect advice already!

I have a G1900 that has been great for many years. All of a sudden one day it would no longer start. I've been all over the web reading posts of what could be the issue. The first thing I did was test the safety switches. I am only aware of of them, one on the seat, one on the brake and one on the PTO for the mower deck. All checked out fine. Next I checked the connection to the ground and battery and that is good. I then took the starter into Advance Auto and they tested on their tester and it powered right up and passed the test. Next I added the Black Box and thought that would the trick. Well it didn't and I am now at a lose of where to look next. Please let me know if there is anything I am missing.

Thanks in advance!

 

[Ramos]

Not at all familiar with the G1900. However, it would seem that there has to be a neutral safety switch for the hydro pedals. I assume it is doing absolutely NOTHING when you turn the key to the start position?

 

[wadeal]

Not at all familiar with the G1900. However, it would seem that there has to be a neutral safety switch for the hydro pedals. I assume it is doing absolutely NOTHING when you turn the key to the start position?

Ramos .. the I believe the safety switch that I described as the brake is the same one that you are talking about as the hydro pedal. And yes the glow plugs will come on but nothing happens when I turn it over.

Also ... I replaced the ignition switch a few years back and would think is still in good shape???

 

[Tooljunkie]

Its a matter of tracing back from starter switch, a wiring diagram would be useful in this situation.
Ignition switch should put power out on the start wire,then its a matter of following the circuit through each component.
First test i always perform is jumping from battery terminal on starter to solenoid start terminal to see if it actually cranks. This tests battery,positive and negative cables and their connections. The complexity of controllers and safety switches is where the wiring diagram would prove invaluable.

 

[wadeal]

Its a matter of tracing back from starter switch, a wiring diagram would be useful in this situation.
Ignition switch should put power out on the start wire,then its a matter of following the circuit through each component.
First test i always perform is jumping from battery terminal on starter to solenoid start terminal to see if it actually cranks. This tests battery,positive and negative cables and their connections. The complexity of controllers and safety switches is where the wiring diagram would prove invaluable.

OK .. I jumped the terminal the starter and the diesel fired right up. It's time to get out the voltage meter and see what I can find out...

Thanks!

 

[rentthis]

That machine has several fuses. One of them would be one the cranking system. You might want to start there.

Mike

 

[Tooljunkie]

That machine has several fuses. One of them would be one the cranking system. You might want to start there.

Mike

As Mike said. Dont just look, grab a test light and test both sides of fuses. Sometimes they look good,and a tiny crack is all it takes. Caught me a few times.

 

[lugbolt]

Those mowers have wiring issues. The connectors are NOT sealed, and many many times I've seen them where the connector will develop corrosion and/or broken wiring/blade terminals either at the connectors or IN the connectors.

Easy test. Start at your source. Battery voltage. Grab your DVOM, test the voltage at the battery. Should be exactly battery voltage. Next, test the voltage at the starter's trigger wire with the key in the start position and all safety switched in the "neutral" position (brake on, PTO off). Keep in mind that the seat switch has no bearing on the starting circuit. You're going to want to see 10 volts MINIMUM at the trigger wire. Likely you'll see zero or something like 7.3 (which is lower than 10 ish). If zero, you'll have to test every switch for +12v into, and then out of, the switch. If low, then you'll have to track it down. Do this test while the trigger wire is still connected to the starter. Then disconnect it and see if the voltage comes up. If it does, you're going to have to do some investigating as to where the problem lies, could be one of the switches or main switch, or wiring/connectors. There is a connector under the radiator that gets dirty. There is another one or two under the steering wheel, one goes to the voltage regulator and that one is notorious for getting burned due to poor connectivity inside the connector.

If you can't find any problems with the wiring or connectors or the main switch itself, and the voltage is just low at the trigger wire, you may find it necessary to install a starter relay kit-which boosts the voltage that triggers the starter to "engage" to battery voltage. This kit is available through Kubota, but I can't remember the part number, and it was something like $94. The John Deere kit is almost identical and cheaper (considerably cheaper)-and just plugs right in. That part number is AM107421.

 

[wadeal]

Well the G1900 is up and running. It seemed that the plug on the ignition switch was either not seated well or the wires were not connecting. I removed the plug to use a multi-meter to make sure the switch was working properly (it was) and when I plugged it back in it started right up. After I had it running .. I went to start it again and it was dead .. no clicking no glow-plugs and was puzzled. I pulled the fuses (again) and checked them all with the multi-meter and they all checked good .. put them all back in and it started right up again. So net-net was a bad connection in the ignition plug and a fuse that was not making good contact.

Thanks again for all the tips!

 

[rentthis]

Thanks for the reply. Many people don't let the group know of positive results.