Could someone please post a photo of the location of the Glow Plugs on the L3710 engine? My .pdf manual photo is poor quality and really difficult to see clearly.
Thanks so much!!
Thanks so much!!
L3710 Glow Plug location
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This is not a photo but should help you find the GP's
Adjacent to the valve cover, above the injectors.
Jointed by an electrical bar tying all together.
Dave
Adjacent to the valve cover, above the injectors.
Jointed by an electrical bar tying all together.
Dave
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Thx Dave - there they are, just staring me in the face! This is my first time with a deisel engine so some of this stuff if totally new to me. Tractor was running great and then when I turned the key it just went "CLICK". The Main Ignition Switch was bad. Removed and replaced after testing it and finding it shorted internally. Have tested all electronic modules, and they all pass, so I have worked my way down the test steps in the book to the glow plugs. Gonna test them tomorrow and see if I have a problem there. Appreciate the help and any suggestions would be welcome. I'm a retired Electrical Engineer, lots of work on Navy aircraft, mainly P-3C Orions - and a couple GTO's, and lots of motorcycles - so this is a new adventure for sure.
Test the glow plugs by measuring each GP's resistance to ground.
Do NOT remove and apply 12 volts to see if they heat up. They are designed to have the head acting as a heat sink moderating the temp rise.
On many newer tractors the GP ON and ON Time is out of your control being set by an engine temp sensor.
Dave
Do NOT remove and apply 12 volts to see if they heat up. They are designed to have the head acting as a heat sink moderating the temp rise.
On many newer tractors the GP ON and ON Time is out of your control being set by an engine temp sensor.
Dave
In addition to Dave's advice, be advised most glow plugs are not twelve volt devices. Many are rated at 10.5 volts and there is some voltage dropping unit external to the glow plugs. On older tractors it was a coil of nichrome wire which also served as an indicator. If you can find one, a schematic of your tractor would be a good thing.
Thx to all for the good advice! How frequent is a starting problem due to a bad glow plug? Or put another way; what is the most common cause of the tractor's starter failing to engage?
The tractor had been running great and I got on to do a job and the starter simply went "CLICK" and occasionally the "CLICK" would be followed by a short buzzing sound.
Checked all the modules under the main panel, found the Main Switch to be shorted, removed and replaced with a new one, and the symptom did not change. Tractor has brand new battery, also.
Getting into the glow plugs appears to be a major deal and I can't help wondering if I have overlooked something more simple before getting into a big project from overlooking something simple.
The PTO switch has not been "On" in quite a while - so I cycled it several times - but no joy.
There's a short somewhere because if I leave the battery connected overnight it will be run down. Also, after the "CLICK" when I turn the Key to Start, panel lights will not alight until I disconnect and reconnect the Positive battery terminal - suggesting a bad capacitor somewhere in the mix.
Any suggestions greatly appreciated!
The tractor had been running great and I got on to do a job and the starter simply went "CLICK" and occasionally the "CLICK" would be followed by a short buzzing sound.
Checked all the modules under the main panel, found the Main Switch to be shorted, removed and replaced with a new one, and the symptom did not change. Tractor has brand new battery, also.
Getting into the glow plugs appears to be a major deal and I can't help wondering if I have overlooked something more simple before getting into a big project from overlooking something simple.
The PTO switch has not been "On" in quite a while - so I cycled it several times - but no joy.
There's a short somewhere because if I leave the battery connected overnight it will be run down. Also, after the "CLICK" when I turn the Key to Start, panel lights will not alight until I disconnect and reconnect the Positive battery terminal - suggesting a bad capacitor somewhere in the mix.
Any suggestions greatly appreciated!
Have full .PDF format file of the Maintenance and Service manual with full, but hard to read, schematics - but I have a decent magnifying glass....
One other thing - when I turn the Key to the "On" position the Glow Plug on the Main Panel does not alight. This is what got me pointed at the Glow Plugs in the first place.
Sure it's not a starter issue?
I imagine it's warm enough in GA to not require glow plugs to start...
I might be way off but that's what jumps in my head!
I imagine it's warm enough in GA to not require glow plugs to start...
I might be way off but that's what jumps in my head!
If the engine is not cranking then I am with Ammobettle that the starter or its ground connection to the engine block is suspect.
The GP's do not affect engine cranking..
Do you know how to jump the starter. Remember all safeties are bypassed and you can get run over or have a run-a-way tractor. Best to have someone in the seat.
When it wont crank, momentarily connect the battery terminal on the starter to the small terminal on the starter solenoid. Cranking should be immediate if the starter is OK.
Dave
The GP's do not affect engine cranking..
Do you know how to jump the starter. Remember all safeties are bypassed and you can get run over or have a run-a-way tractor. Best to have someone in the seat.
When it wont crank, momentarily connect the battery terminal on the starter to the small terminal on the starter solenoid. Cranking should be immediate if the starter is OK.
Dave
The most common cause is like that of Orion sea spray - bad connections, one very likely being the negative conductor from battery to frame.
At this point the glow plugs are a symptom and not a cause. Nice warm GA WX and heat of compression on crank will take the diesel to combustion.
I would attack this by separating the power subsystem, the starting subsystem, and the safety subsystem. The only new stuff for you would be the glow plugs, operator presence control (OPC), lack of spark plugs/ignition system.
Dave suggests isolating the starter subsystem and checking function. Good idea.
You state that there is a problem in the power subsystem. OFF should mean OFF. Get an ammeter hooked in and start pulling fuses one by one. You may have to finger feel harnesses to look for rubbed or chafed insulation.
I would leave OPC functionality for last.
Detective work with a wiring diagram copy and a highlighter. Nothing that you haven't done before.
Dave, You're advice sounds spot on, I'll have some help Friday and will have cleaned and verified the Glow Plugs and the flat conductor that connects them. Four times over the past 2 years the tractor would not start and the problem proved to be simple galvanic corrosion in the fusebox, fuses, or a connector - a good clean and polish solved these problems. The positive cable (from the battery) to the Starter had a damaged area of insulation near the rearward attachment point. That cable is at the top of my test list for tomorrow. Prehaps the rodent problem is worse than I supposed! Thank you. Will post results in due course.
Jim, Your advice dovetails with Dave's, and a starter going bad after 22 years should come as no big shock. We have been ignoring a small area of rodent damage in the main Positive battery lead. Been needing to buy a new ammeter, and here's the excuse! All previous problems have been caused/repaired by a good corrosion control cleaning, but it looks like we may actually have a bad part this time. I'll get out of my own way and follow up on Dave and your advice first. Thx very much.
Thx for the very valuable info. Knowing about the heat sink function of the engine itself has saved me a lot of possible misery and $$$.
Jim,
Picked up a Southwire 21550T today, the last one at my local big box and marked down to under $85! Can't remember how many times I told my people "OFF means OFF" when they had a cold solder joint, etc. on a panel switch. Thx for kicking me out of my coma overlooking the main clue. Expect to have the Little Orange Tractor diagnosed by lunchtime tomorrow. Appreciate the good advice and reminding me of the basics as I went down the maintenance list, in order, in the manual.
Picked up a Southwire 21550T today, the last one at my local big box and marked down to under $85! Can't remember how many times I told my people "OFF means OFF" when they had a cold solder joint, etc. on a panel switch. Thx for kicking me out of my coma overlooking the main clue. Expect to have the Little Orange Tractor diagnosed by lunchtime tomorrow. Appreciate the good advice and reminding me of the basics as I went down the maintenance list, in order, in the manual.
For someone armed with a new meter, this DENSO starter trouble shooting process is quite comprehensive.
https://densoautoparts.com/Portals/...s/file/DENSO Starter troubleshooting tips.pdf
Dave
https://densoautoparts.com/Portals/...s/file/DENSO Starter troubleshooting tips.pdf
Dave