Dead tractor: Electrical or Mechanical, what next?

[apriordan]

2005, 790 diesel died while operating.

Headlights blew, then taillights, drove in the dark for a minute or two before eventual fail. At which point I panicked and added diesel fuel additive.

Would crank after died, but not start. Some thought gel fuel, but it had been running/operating for 2-4 hours. After this time, we tried jumping with no avail and added diesel 911 (to permiate through the system).

Subsequently, I identified that fuse for headlight, taillight and more importantly fuse for fuel pump had blown. Now, it's dry locked right? In reading online JD maintenance manual the tractor has a self bleeding system, just crank it over for a while. Kept trying that, no luck.

In keeping with gel fuel or dry locked, I removed fuel filter and added diesel 911 plus new diesel fuel (approx 50/50). New ground wire installed to upper sheet metal at rear of battery compartment (which also holding radiator engine bay side and air box bracket/arm on battery bay side). Tried to start while jumping and after heating oil pan and having battery on maitainer. No luck, didn't crank. Thought needed new battery.

Checked power to starter from battery and yes it has power. Tried using multimeter and was not getting any reading/movement. Simple bulb power indicated it was getting power. Tried jumper cable from battery to starter and no luck. Tested fuel pump and other circuits all had power, uncertain of voltage as multimeter challenges.

Replaced battery, with new. And still won't crank. Dash lights on, but nothing. Where do I go from here?

 

[Bavarian]

Be careful with 911, you can dry out the fuel and damage parts that are lubricated by the fuel.
You did pretty much everything on the troubleshooting side.
Can you connect the ports on the starter with a screw driver while the jump wires are there?
Does the solenoid click? With your blown fuses, it sounds you have a major electrical problem, which could be the starter.
Is the engine seized? Try to move it by turning the fan blade, put a wrench on the crankshaft if accessible, or you have a chance at the flywheel . If the bellhousing is open try it with a screw driver, get a lever at the housing and try to turn the flywheel.
Are there any safety switches, like tranny in neutral? Seatswitch?

If everything turns out ok, I would bench test the starter.

 

[Bavarian]

Do you get a start signal to the starter solenoid? It's the thin wire. Should have power while the key is in start position.

 

[TemporaryKubotaOwnerMark]

Stop thrashing around throwing fixes at it!

Something made your fuses blow. Fuel doesn't do that. Find the electrical problem first, then you can worry about the fuel system.

 

[beenthere]

To check for a short, put a 12v light bulb in place of the fuse.. if it is lit, then something is causing that to short. When the bulb is out, then the circuit is free of a short.

I take a dead fuse, and solder wires to a light bulb socket to the prongs on the dead fuse to make it easy to plug in. I find it easier to see a light glowing out of the corner of my eye than to watch a needle on a volt meter.

 

[Coyote machine]

You need to isolate the problem to fuel, electrical, or engine before jumping to conclusions, like a new battery.
Start by telling us what exactly is going on at this point. Simple descriptions: I turn the key to crank and this happens.... etc.
After replacing the fuel pump fuse this happens....
Post back where things are at....

 

[RNeumann]

Stop thrashing around throwing fixes at it!

Something made your fuses blow. Fuel doesn't do that. Find the electrical problem first, then you can worry about the fuel system.

Total agreement with this one. You are shot gunning this instead of taking a logical and mythical approach. Start with electrical. What caused the fuses to blow? Check battery voltage, major short, bad ground, alternator function etc. I'm betting once you have the fuses replaced and have verified all electrical function the machine will rise again!

 

[apriordan]

Stop thrashing around throwing fixes at it!

Something made your fuses blow. Fuel doesn't do that. Find the electrical problem first, then you can worry about the fuel system.

Ground wire was good, fuse was blown from all the cranking I did yesterday? Replaced one of the PTO fuses and it started right up.

 

[apriordan]

Total agreement with this one. You are shot gunning this instead of taking a logical and mythical approach. Start with electrical. What caused the fuses to blow? Check battery voltage, major short, bad ground, alternator function etc. I'm betting once you have the fuses replaced and have verified all electrical function the machine will rise again!

Ran first series of troubleshooting to include electrical (fuses) after I replaced them with new, same day and next day didnt work. Where i made the mistake was on my second round of troubleshooting, i failed to inspect the fuses again. I didn't expect any to blow. Replaced a PTO fuse and it started right up.

What do they say, an engine needs three things to run; fuel, spark and air? I need to next level that with the electrical systems, for spark you need ground, 12v and x, y and z.

Man, that was a painful learning experience.

 

[beenthere]

:thumbsup:
Glad to hear you tracked it down...