I was running my John Deere 892 elc excavator the other day and the battery light came on. Shut it off and now no crank. Oil light buzzer comes on and the only way to shut it off is to pull a battery cable. Would a bad alternator cause no crank?
Welcome to HEF Davisfisher ! If you ground the blue/yellow wire that is attached to the D+ terminal of the alternator, will it then start?
I did, still no crank
Did the alarm stop and the monitor shut down when grounded?
Yeah I had no power then. I had to put an alternator resistor in after that
The blue yellow wire has 23 volts at it
Could it be the key switch? I tried a new battery relay and it still stuck on. But no crank
I can jump the start relay and get it to roll over
Please post the entire machine's serial number. Need this because that circuit is slightly different depending on the serial. Was that measured with the wire connected to the alternator or not? If it was measured when disconnected from the alternator, then it would have 24 volts. If it connected to the alternator and you measured 24 volts with the key on/engine off, then the regulator within the alternator is defective. The monitor is looking for that wire to be grounded when keying on, or when shutting down. When you key on, and the monitor sees voltage, whether it is due to a defective regulator or from an open blue/yellow wire, it thinks the engine is running and will not allow it to crank. Same with shutting it down. If the wire does not become grounded, it thinks the engine is running, sees no oil pressure, then activates the alarm. When you disconnected the blue/yellow wire, grounded it to stop the alarm and shut down the monitor, did you leave it grounded when you tried to start it again?
Vin number Ff892ex011637 The wire had 24 volts when it was disconnected from the alternator. I took the alternator in yesterday and had it tested. It tested faulty. So the machine wont crank with a bad alternator? When I grounded the blue and yellow wire it burnt up the alternator resistor
It shouldn't have. That is what the resistor is for. That voltage gets grounded through the regulator so the resistor prevents wire melt. Yep. if the regulator does not ground that wire, then it can cause your exact complaint.
Okay new alternator and still won’t crank. I can jump the starting solenoid to crank though
With the wire connected to the D+ terminal, what voltage is there with the key on? Is your alarm/monitor issue fixed? Check your messages.
Okay I got the exavator to start today. I just have to unhook the alternator resistor. But then it won’t shut off.
Check your messages.