Deere 4100 Not Starting

[jgbanshee]

I cannot get my JD 4100 to start. When I turn the key it just cranks. If I play with the PTO switch on the dash a bit, I can start it occasionally. I could hear the fuel solenoid right before I crank it and starts. When the tractor was working properly, I could here the fuel solenoid all the time when I went to start the motor. How can I jumper the PTO switch to test? Is the PTO switch even the problem?

 

[jd110]

The pto switch can be the problem. They are usually very reliable. Check it with an ohmmeter. It should have continuity between terminal A & C when switch is off. You should have 12 volts coming into switch on red wire at terminal A and power flows to terminal C and from there to fuel control module terminal D. This is a brown/white wire.

 

[kennyd]

A defective PTO switch would keep the starter from cranking wouldn't it?

 

[RoyJackson]

A defective PTO switch would keep the starter from cranking wouldn't it?

Any of the safety switches should prevent the starter cranking (as Kennyd knows...)

So, I'll make my usual suggestion...first, try jumping from another battery. Even if jgbanshee's starter does crank, it may not be cranking fast enough.
Don't tear into anything until you've exhausted all the external possibilities (corrosion on the battery or starter cables and ground cables is a good start, if the jump doesn't work).

 

[JD755]

Make sure the fuel solenoid is remaining engaged. One coil in the solenoid will activate for starting, but a second coil needs to stay activated during run. The A2 control module, with inputs from safety systems, controls that. It can seem that it won't start when it actually does but in that very brief instant you sense it firing and return the key to Run it stops because the hold solenoid did not work. Overall impression can be of it just not starting.

 

[RalphVa]

I'd check your fuses. The one for your fuel solenoid may be burned. Of course, the fuel solenoid may be gone.

Think the fuses are under the hood on the right side, just behind the instrument cluster, near the radiator overflow tank.

He says it's cranking, guys. Sounds as though the fuel solenoid isn't staying open if a jolt (from playing with the PTO switch) causes it to open momentarily. Now that I say this, it doesn't make sense that it would be a fuse. So, it must be one of the other switches somewhere that is keeping the solenoid from opening. Since you've played with the PTO switch and gotten it to start and die, it is suspect.

One thing you might want to try that bypasses the PTO switch interlock is to raise the driver's seat and pull up on the little black switch beneath it. It's there to allow you to run the PTO with no one in the driver's seat, like for a chipper/shredder. This switch doesn't work on my 4010, but others with 4100s have reported it working. You might have to pull the PTO switch up and also pull this one up to work the bypass.

 

[jgbanshee]

JD110 - I plan on checking the PTO switch more. Thanks for the direction. RoyJackson - It has a new battery in it. JD755 - the tractor normally made a 1sec buzz noise when I turned the key and it would start. Now it will only make the buzz while playing with the key switch and/or PTO switch on dash 1 out of 50 trys and it will start. No buzz = no start, just cranks. RalphVa - fuses checkout fine.

 

[JD755]

That buzzing is the pull-in coil in the fuel shutoff solenoid. JD has used different methods for engaging that pull-in coil. Mine is connected to the starter and is on while cranking. Late models use a positive temperature coefficient (PTC) thermistor that heats up and increases electrical resistance. Your 4100 uses a timer in the A2 control module. That timer interval is one second. The inputs to the control module include the PTO and seat switches. Of course there could be something intermittent with the solenoid or control module, but sounds more likely to be one of the inputs to the module. Besides checking the switches, also check all connectors. Unplug and re-engage them. Clean them if necessary.

 

[jgbanshee]

I looked into the PTO switch. I cannot figure anything out. Before the problem existed, I could turn the key once and the parking light would blink. Since the problem, the parking brake light does not blink unless I pull the PTO switch up and down once. I tried disconnecting and reconnecting all harnesses, I pulled the switch under seat up, moved the PTO lever between front/mid/rear. Nothing helps.