Help! JD 770 Dead!

[kennyd]

I think the clue here is he unhooked the hydro lines off the remotes and the ENGINE labored. He then shut if off and when he tried to restart he heard the pop!

If you read his post, he restarted after connecting the backhoe lines:

when I dissconnected the hoses the tractor labored a little and when I heard that I immediately shut it down. I connected the backhoe hoses to the tractor in preperation to adjust the subframe and when I turned the key........POW!

 

[kenstrac]

.......and when I put the negative side of the tester on the selenoid and the positive at the lead......shows voltage which means something is closed? if it were open it would not register voltage.[/QUOTE]

Explain better where where you are putting test leads almost sounds like you have a poor ground.or a poor connection on the hot side
Put yor lines back as if there is no bh on it with key off in high gear rock tractor back and forth listen if you hear starter snap back.

 

[Diamondpilot]

If you read his post, he restarted after connecting the backhoe lines:

I dont think it started after he shut it down. It went POW when he tried to restart. Either way he has big problems.

Chris

 

[Whitey]

OK.....I spoke with the JD service manager this morning.....I explained the situation completely to him. He said that I should not have hurt the hydro pump.....it would have taken a very high idle and some time to burn out. He also said that he felt that the hookup to the BH was a coincidence

Any way he said that I should start with the battery (just as AKfish said) and trace through the starter and selenoid. Can someone please explain wher I am to remove the starter at.....there is a large plate at the base where it bolts to the body or there are two long bolts that look to hold the starter and I think those are the ones to go for.......can anyone confirm??

 

[kenstrac]

I would not take the starter off yet not till you trouble shoot the problem.I would put the meter on the wire that comes from the battry that is on the starter and other test lead to ground on the starter and turn lights on and see if the voltage drops.

 

[Cocre]

I would replace the battery. Take a good unit out of another vehicle and try it. Do not jumper one to the other. A dead short in the battery would prevent a jump off from working.

 

[crashz]

Whitey,

I'm also thinking that its electrical. So no dash lights, no headlights when key is on, and fuses OK, hot lead from ignition to the starter solenoid send juice, and hot lead from battery is live? I'm thinking its the starter solenoid or the connection at the hot lead(s) at the starter are corroded and are not giving you power correctly. Corrosion will do funny things.

I think the pop was electrical, but I have another question for you. Did you have the headlights or anything drawing electrical current on while operating the tractor at idle? Its possible that the battery was drawn down enough to reduce voltage and increase current draw enough to "pop" something. What condition is the battery in now? Can you try another battery just for kicks? Have you checked and cleaned the grounds gound to the body and the engine?

 

[irwin]

I would not take the starter off yet not till you trouble shoot the problem.I would put the meter on the wire that comes from the battry that is on the starter and other test lead to ground on the starter and turn lights on and see if the voltage drops.

I would replace the battery. Take a good unit out of another vehicle and try it. Do not jumper one to the other. A dead short in the battery would prevent a jump off from working.

Both these are good advice, put a known good battery in it......if it doesn't fix the tractor.. then do a trace for open or short (component and connection check)

BTW a loud POW noise is an issue that should be answered..get a look at the pigtail side of the ignition switch (where you said the noise came from) you might see a sign of heat damage somewhere...

The starter is removed by unbolting the whole starter from the block (2 bolts) it's on the left side.

 

[dqdave1]

You have gotten a lot of good advise so far. To recap;
1. Remove battery and have it checked at an auto parts store.
2. Inspect the positive and negative battery cables; clean ALL ends. If possible; check continuity of both cables while wiggling them. Make sure gound wire at frame is clean and tight.
3. Check starter switch closely; can you remove it?; does it smell llike it burnt? Using a tester; bench test all poles for correct operation.

4. Check primary wire from start switch to starter for continuity. ( you may have an internal break in a wire from surge that is not noticable to eye.) Wiggle wires while watching omh meter.

5. Check the fuse link again.

6. IMHO; sounds like a grounding issue or battery issue.

GOOD LUCK

 

[banjodunn]

G'day Whitey i think you are heading in the right direction with checking the battery for starters but when you do don't overlook the obvious dirty battery terminals they can give you a reading with your meter but as soon as the load of the starter comes on zilch also check all your connections are clean and tight if you find all good and you are getting 12v down at the starter on both the main and the trigger wire you have probably got a starter at fault, to remove this do not undo the two long bolts as these are the tie bolts that hold the starter together you need to undo the larger bolts where the starter mounts to the gearbox bellhousing also chris i think what you are referring to is called hydraulic lock when water fills the cylinder i.e a blown head gasket it cannot be achieved by a hyd pump blowing and dumping its guts into the sump, to achieve hyd lock you have to fill the cyl with a liquid not possible i believe unless the engine has had a long time to sit and the engine is overflowing with hyd oil