Fuel shutoff solenoid question.

[woodsy]

Been having some quirky electrical stuff going on with my new to me 95' L3300.
Sometimes it has been shutting off with the key other times not. Last couple times not
and now won't crank over at all. Glow plug, battery and oil symbols light up and battery has 12.75 V
as does the connection at the starter but won't crank , not even a click. . Shutoff solenoid feels hot after repeated attempts to start it while
checking out connections. Any suggestions or tips appreciated before I buy any new parts.

 

[Dave_eng]

The Operators manual available from Kubotabooks.com contains valuable insight into the safety systems that could prevent starting.

At the very least you must have safety switches not working properly.

Jump the starter but doing so bypasses all safety systems and can get you killed or end up with a runaway tractor. Have someone on the seat with brake applied when doing this.

If the tractor turns over jumping the starter you have proven the starter is good. If it will run (key switch ON) then the stop solenoid id OK.

If it wont turn over with jumping then you have battery or battery cable issues.

Dave

 

[kubotafreak]

New shut off solenoid sounds like the right answer. Unplug it to see if it is causing your issue.

 

[lugbolt]

check the ground

it goes from the battery to underneath the battery and that area is well known for issues. I just cut the stupid thing off and run a whole new ground cable from the battery to the engine or frame, then paint over it real good so it won't rust/corrode.

U can do a voltage drop test and find your issue. I've explained it here before and...well frankly I'm too lazy to explain it again. Search for it. Once you learn how it's done you'll be able to isolate all sorts of electrical issues.

 

[woodsy]

Thanks for the checklist Dave. I'll work through that 1st.
Already reworked the ground from the battery, did that last week.
Had a neg. ground strap (heavy duty) hanging on a hook and got that attached
to the frame under the radiator . That worked wonders.
Probably something simple just need to get familiar with it all.
Big advance moving from a 50s era to a 90s era tractor.

 

[woodsy]

Starter works when jumped, fuel shutoff solenoid working visually.
Main ignition switch contacts (4) all look good, tight.
Hard telling whats going on in the switch but the relays will be the last check.
All shifting controls in neutral and PTO off position. Wiggling stuff around
while turning key to start, nothing except dash symbols.
Continues to scratch head.
At least I have my 51 JD that I can count on to start, better keep it.
edit:
Started it with a jumper cable at the starter, runs good, shut it off with the key,
unlike last time it ran. Would not restart with key.
Thinking I've narrowed it down to either the ignition switch or a starter relay .
Any best guesses ? Not much of an electrical guy, nuts and bolts are easier.
Thanks

 

[woodsy]

As it turns out the neutral safety switch was the problem.
Unscrewed it from the shifting lever bracket for a closer look
and it looked all tarnished so ran some 400 grit sandpaper between
the contact points , reinstalled and started right up and shut down properly by key.
Refreshing the safety switch contact points or replacing the switches if worn badly will now be part the annual maintenance . I will probably replace this one. FWIW.

 

[Dave_eng]

As it turns out the neutral safety switch was the problem.
Unscrewed it from the shifting lever bracket for a closer look
and it looked all tarnished so ran some 400 grit sandpaper between
the contact points , reinstalled and started right up and shut down properly by key.
Refreshing the safety switch contact points or replacing the switches if worn badly will now be part the annual maintenance . I will probably replace this one. FWIW.

Thank you for posting the solution. It helps everyone learn!

Dave

 

[PoTreeBoy]

As it turns out the neutral safety switch was the problem.
Unscrewed it from the shifting lever bracket for a closer look
and it looked all tarnished so ran some 400 grit sandpaper between
the contact points , reinstalled and started right up and shut down properly by key.
Refreshing the safety switch contact points or replacing the switches if worn badly will now be part the annual maintenance . I will probably replace this one. FWIW.

Sounds like it's exposed to the elements. You might try smearing a little dielectric grease on the contacts.

 

[Mark_BX25D]

Not much of an electrical guy, nuts and bolts are easier.

For some one who's not much of an electrical guy, you sure did a great job wrestling this one to the ground.

 

[woodsy]

Just got lucky, started with the PTO switch and moved on to the neutral switch not to mention going over everything else prior. Took a few days to stumble upon the problem but happy now, ready to work it some. Only had it for 3 weeks.
Big upgrade going from a 51 JD with no safety switches, 3pt hitch, 4x4 or FEL !
Thanks to everyone for the troubleshooting help.

 

[torch]

Sounds like it's exposed to the elements. You might try smearing a little dielectric grease on the contacts.

Dielectric grease is an insulator. Great around the edges of a connector to keep moisture out, but you don't want that on the contacts. Deoxit D5 is a contact cleaner that leaves a conductive protective film. Kopr-Shield is a copper-laden conductive grease. Either would be a suitable choice. Neither is particularly cheap.

 

[GeoHorn]

Dielectric grease is an insulator. Great around the edges of a connector to keep moisture out, but you don't want that on the contacts. Deoxit D5 is a contact cleaner that leaves a conductive protective film. Kopr-Shield is a copper-laden conductive grease. Either would be a suitable choice. Neither is particularly cheap.

I disagree.

First of all...the basic electrical path is from direct mechanical contact ...not from some magic goo. If you don’t have good mechanical contact...you don’t have a good electrical circuit and no “Goo” is going to fix that.... BUT... conductive greases MAY create an electrical pathway to places you do not want.

The dielectric grease protects that mechanical contact from corrosion and contamination. Clean the contacts, see that they are firmly connected, use dielectric grease.

 

[torch]

The electrically conductive grease protects the mechanical contact from corrosion and contamination -- without leaving a film between that increases the resistance of the connection, drop in voltage and increase in heat like a dielectric grease.

Don't apply it like a 3 year old with lipstick. Use a q-tip, toothpick or similar and colour between the lines like a 6 year old.

 

[Mark_BX25D]

Dielectric grease is an insulator. Great around the edges of a connector to keep moisture out, but you don't want that on the contacts. Deoxit D5 is a contact cleaner that leaves a conductive protective film. Kopr-Shield is a copper-laden conductive grease. Either would be a suitable choice. Neither is particularly cheap.

Oh, this tired old wive's tale again. *sigh* Will it never die? Probably not.

Dielectric grease is MADE FOR CONTACTS. That's it's whole purpose in life.

"Conductive grease".... isn't.

Dielectric Grease vs Conductive Grease

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http://forums.sohc4.net/index.php?topic=82814.0 (Read the WHOLE thread, not just the first post which reiterates the bad info.)

Jeep Articles / General (Dielectric Grease) - MoabJeeper Magazine

 

[torch]

Oh, this tired old wive's tale again. *sigh* Will it never die? Probably not.

Dielectric grease is MADE FOR CONTACTS. That's it's whole purpose in life.

Actually, the purpose of dielectric grease is to seal and lubricate spark plug boots.

Applying it to electrical contacts relies on a mechanical wiping action squeezing the grease out when the connector is mated. In reality, when used with a low-pressure connector, what happens is that the high spots are (hopefully) pushed through the grease film to make metal-to-metal contact.

Basically, the same thing happens with electrically conductive grease, such as Kopr-shield. The difference being that the copper particles fill in some of the microscopic scratches so the metal-to-metal surface area is greater.

What difference does that make? To a hand-held ohmmeter, virtually none. The meter has a small battery and a high impedance and does not impose a significant load. As power goes up, the difference becomes measureable.

Rather than rely on internet gurus, I prefer to look to the manufacturer. From a Permatex document:

"Dielectric grease, or tune-up grease, is a silicone-based grease that repels moisture and protects electrical connections against corrosion. It is also used to keep dirt, water, and other elements out of electrical connections. It has many uses, including automotive tune-ups, home electrical work, and recreational vehicle wiring. Dielectric grease does not dissolve in most liquids, so it is good for marine and outdoor applications. You can use this grease to lubricate the rubber parts of electrical connectors, spark plug wires, and to protect electrical connections on your boat or recreational vehicle from corrosion. Since dielectric grease is a silicone grease, it should not be used on silicone-based rubbers or plastics, as it will break them down over time. The grease does not conduct electricity, so it shouldn’t be applied directly to the mating surfaces (pins and sockets) of an electrical connection. "

Your tractor, your choice.

In any event, neither will remove oxidation. My first recommendation, De-oxit, will remove oxidation and leave a protective layer. I back that up with dielectric grease applied around the connector shell, including the back side of unsealed connectors.

 

[Mark_BX25D]

Clearly, you didn't bother to read the sources I cited. I could multiply them by the hundreds if I cared to take the time.

In any event, neither will remove oxidation. My first recommendation, De-oxit, will remove oxidation and leave a protective layer.

Oh! A "protective layer"!! Yes, of non-conductive material, just like dielectric grease.

Of course, since they refuse to disclose the components in the MSDS, we don't have the opportunity compare anything meaningfully. All we have are the manufacturer's unsubstantiated and untestable claims. "For reference, DeoxIT® D-Series has approximately 20% cleaning action." Of course, the discerning reader will note that this claim really doesn't say anything. Very much like, "Compare at $29.99!", it makes the gullible reader assume that some specific claim has been made, but actually, nothing testable has been said.

As for the " mechanical wiping action", well, duh. Just like is found on almost all automotive connections. The only other kind are in sealed units, like some electronic switches or inside of relays. Of course, the reasonably intelligent person recognizes that these are not under discussion.

The only other kind of connection is where threaded fasteners are used, typically with a ground connection. In these, there is a significant measure of wiping action, but even where there is not, there is sufficient contact pressure to displace the dielectric down to a few microns where it is no longer an insulator, but does provide a barrier to corrosion, as proven by decades of use in many different industries, including aerospace and military applications where life depends on things working.

 

[torch]

Clearly, you didn't bother to read the sources I cited. I could multiply them by the hundreds if I cared to take the time.

There are an equal number of sources that state the opposite.

Your tractor, your choice.

For the record, I base my choice on the advice of a personal friend who is an electrical engineer with Siemens, and who has specific knowledge and experience in the design and installation of electrical connections of a wide variety of voltages and currents in severe environments. He has decades of experience.

My choice of Deoxit is based on personal experience with the product. I was first introduced to it many years ago when restoring old electrical test equipment with oxidized switch contacts and have since found it very useful in rejuvenating automotive connectors. It won't fix connectors that are rotted away, and it won't fix green corrosion growing up the wire strands, but then, neither will anything else.

 

[Mark_BX25D]

There are an equal number of sources that state the opposite.

Of course there are tons of uninformed people spouting the same ignorant line. I like the way the fellow on the Jeep forum put it, "Run, Martha! That thar's a INsoolator!"

It's pure ignorance.

of a personal friend who is an electrical engineer with Siemens, and who has specific knowledge and experience in the design and installation of electrical connections of a wide variety of voltages and currents in severe environments. He has decades of experience.

Oh, one of my colleagues! He should read the literature. Of course there are places where neither dielectric grease nor any other product should be used (like high frequency connections, which is my specialty), but standard automotive connections ain't on that list.

My choice of Deoxit is based on personal experience with the product.

It might be a good product for the purpose. (And at least you are not recommending No-Alox or some other compound intended for aluminum power connections.) But so is any decent dielectric grease. My problem is not with your favorite product (though I tend not to trust companies that use weasel words like, "Compare at!", or "20%" with syntax which says absolutely nothing), but the ignorant idea that dielectric grease should not be used on electrical contacts.