3020D Starter Issues 24V

[BrotherJoe]

Hi All,

I've got a 3020D still running the 24V system. This spring I had the starter rebuilt (it was cranking slowly, and ended up needing a new armature--it was cooked); upon putting it back on I found that sometimes it would not engage... but after a few tries would. I lived with it for the summer, but, very occassionally it would stick "on", but disengaged and not cranking the motor. This past weeknd it got worse--yet I found if I knocked on the solenoid with a wrench, it'd stop spinning--but often it would continue to spin after I started the tractor so I'd have to listen for it and give it a few whacks.

I finally had time to take it down to the guy that rebuilt it, nice local guy that's familar with the 24V's and has rebuilt lots of these.

On the bench it was fine, but, he felt bad I had to pull it and puled the solenoid apart; put a new disc in the solenoid, and put a new pin/keeper in the fork (the other was a bit worn). I got home, put it on.. same exact issue; only now I can't seem to git it to disengage with a whack, I had to unhook the neg battery cable.

To be clear:

Battery connected, key on, button push; ~75% of the time, starter won't engage to crank engine. 100% of the time once I push the starter button, it seems to just runaway. ~50% of the time if it engages and cranks the engine, the starter continues spinning until I unhook the battery again. If I hook the battery back up, no problems, the starter stays off until I attempt another start of the engine.

I saw a recent thread on a 3010 12V that was staying constantly engaged with battery connected, this is not the same symptom as me-and it appears that poster found a wiring fault at the circuit breaker?

Ideas on this one? I've heard that with low cranking voltage the solenoid will arc and weld itself--but I don't know how that jives with it not engaging to crank the engine. Given how it's behaving, it's almost impossible to do a voltage drop test without burning up the starter because it somebody has to be ready to unhook it.

EDIT:

I did some more quick probing around.

1) if I take the starter button out of the picture and just jump the terminals with wire, same behavior.
2) I probed the yellow starter button wire and can't find that its inadvertently grounded--probed through the neut safety switch back to S terminal.
3) What voltages should i be seeing with everything off?

Between G lug on solenoid and the S lug on solenoid, I see 25+ V, with everything off. Same between G and the 2 lugs on back of starter joined by copper strap.

It's hard to check cranking because I have to reach down and unhook the negative from the battery to get the starter to stop spinning; but it's over 24V.

Thanks all!

Joe

 

[tim s]

I don't understand why any one would waste any time fighting with a 24 volt system,,,,switch it to 12 volts and Life will be better.......

 

[ET]

I think you have a low voltage issue. I would check all the battery and ground connections. If you have any of those worthless clamp on battery cable ends get rid of them. Resistance between the cable and battery terminal clamp is responsible for destroying a lot of good 24v systems.

 

[BrotherJoe]

I'll pull the floor up and re-verify. I gave the posts and terminals a scrub with a wire brush when I put the starter back on and then the B battery terminals as well. The A battery neg terminal may be crusty--as is the fuse to ground (though.. I blew the fuse twice while fussing around with it).

Are there other problem points? Behind the dash?

Looking at this schematic (color one)

https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=1896433

Maybe something in the key-switch? I have replaced both the light switch and the starter switch to no avail; but it seems to me that the important starter connects are after the key-switch.

I need to find the A batt pos ground connection, that must not come right off the terminal like the A neg fused connection.

 

[Tx Jim]

(quoted from post at 07:14:43 08/16/19) I don't understand why any one would waste any time fighting with a 24 volt system,,,,switch it to 12 volts and Life will be better.......

I agree 100%. Life is too short to fight the gremlins that the JD 24 volt electrical system have. I know some people have great success with the unique 24 volt system but I had all the FUN I ever wanted yrs ago trying to keep the 24 volt system operating correctly.

 

[BrotherJoe]

I understand people don't like the 24V.. at the moment, it's what I have. It also seems that whatever is fishy in there, is also, not going to go away magically by switching things to
12V, because there is still something amiss.

I thought of another question; Maybe I don't fully understand how the solenoid/starter engagement works. My understanding is that with proper voltage, solenoid engages, fork goes
forward and brings the gear forward to the ring gear on the motor. That isn't reliably happening for me. More oddly; if it does or doesn't come forward, the starter will still engage
and spin--but won't *stop* unless I unhook the battery. That doesn't make sense to me; I can see a low voltage issue making the solenoid chatter and not engage (I think), but I can't
explain the starter spinning endlessly.

What interaction am I missing there that may help me narrow my search.

 

[Tx Jim]

When starter engages but doesn't stop spinning the washer(key 7) inside solenoid sticks to contact lugs(keys 2 & 6) inside the cap.

 

[tim s]

I know that is what you have,, and I understand that,,,but your issues will go away when you go to 12 volts,,there are "Many" things that will mysteriously drain your battery's with 24 volts....The money you will be wasting on the 24 volt repairs will make the switch to 12 volt and do away with the problems you are having...

 

[MSM]

Have you tested the batteries? Old or
missmatched batteries. Low cranking
amperage will"spot weld" the solenoid
contacts giving you the problem you
have.just because it shows 25 volts doesn't mean you have adequate amperage to energise the solenoid and spin the starter properly.

 

[buickanddeere]

As others have stated . Your tractor has VD and burned the starter.
Tims is a wizard and has the 24 to 12V down to a science . There is a short length, high torque 12V Iskra starter that directly bolts in.
2/00 welder cables, ground cable to a starter mounting bolt , new battery box with 1000CCA group 31 battery and good to go.

 

[Dan in North Houston]

I fought the 24v problem on my 4020 for several years, finally bit the bullet and got a whole new custom wiring harness from wiringharness dot com, alternator, and starter. The whole process was pretty straightforward and now I have a tractor that starts, and all of the lights work. Still kicking myself for not doing it years ago.

 

[BrotherJoe]

(quoted from post at 15:00:06 08/16/19) I fought the 24v problem on my 4020 for several years, finally bit the bullet and got a whole new custom wiring harness from wiringharness dot com, alternator, and starter. The whole process was pretty straightforward and now I have a tractor that starts, and all of the lights work. Still kicking myself for not doing it years ago.

Ok, All. TimS, TXJim..etc.. Nothing like getting to the end of the week after a long week of work and taking one last look at a 6000lb paperweight parked in the middle of the shed to reduce ones appetite for being stubborn and "finding the problem" versus just knowing when to listen and move forward when the prevailing opinion is clearly that this is a battle that nobody wins in the end..

Lots of 24-12V conversions available on the net--what do I need/want to get?

Thanks,

J

 

[MikeinKy]

Tim is exactly right. I did the same thing for years. Been there and done that. I now have two 4020's with 12 volt alternators, and they never give me any problems. Batteries stay up, don't burn off battery posts, always start.

 

[Tx Jim]

BrotherJoe
To change your tractor to 12 volts you need to get a starter similar to one show below, then when installing 12 volt starter relocate brown wire in photo below to top post on solenoid along with blue wire,install a 1 wire 12 volt alternator. One also needs to change fuel gauge to one with different polarity RE53664 gauge and the AR26434 sender. You can get gauge/sender from EverGreen Restorations 715-635-8629. Change battery cables to where batteries are connected in parallel)12 v) not series(24 v).

https://www.external_link.com/starter-iskra-plgr-18483-new-bobcat-6651258-155226.html?

 

[D-]

You probably will/should do the 12V thing but your problem might be
mechanical instead of electrical. Perhaps the splines on the armature
are not just right since that issue started with armature replacement.
Burs on flywheel but it wasn't doing it before?

 

[BrotherJoe]

(quoted from post at 08:14:48 08/17/19) You probably will/should do the 12V thing but your problem might be
mechanical instead of electrical. Perhaps the splines on the armature
are not just right since that issue started with armature replacement.
Burs on flywheel but it wasn't doing it before?

I see where that could be an issue. I have 3 things that I really need explained. I think everyone is too blind with "24v is hell, and it sucks" to really give any other opinion.

My largest concern before going down the 12V route is that there is actually an electrical problem that *does not* go away magically by converting to 12V. Since no-one has really explained some of the symptoms other than by saying "12V is going to save you headaches".. I'm still wanting to get to the bottom of electrics before I do that.

I load tested both batteries with a tester, both test on the very high end of good, so, to my mind I do not have:

1) Melting battery posts.
2) A slow drain on the batteries due to dust in starter (which was rebuilt..).
3) With tractor idling, I do see batteries charging/haven't had any problems with batteries being low.


The one thing that I think negates mechanical/burrs on the flywheel is that the starter will continue to run, even if it has not engaged, until I unhook battery. Now, this could be the solenoid welding self closed, but, why would pulling voltage solve that? Turning key off and stopping depressing starter button have no effect.

I could see how the burrs could be a culprit if either the starter gear weren't able to find a smooth spot into the ring gear and would bang and miss and a few tries would get it into a lucky alignment.

I'm assuming both circuit breakers on the starter body are fine--what else goes bad in this path?

An oddity I note is that A battery POS should be grounded straight to frame--I can't figure out where that happens, it doesn't happen off the post/terminal.

The NEG is grounded through a fuse, which has blown several times while running though everything (3A).

 

[Tx Jim]

Joe
i think after serving 13 yrs as a JD dealer service manager during the hey day of 24 volt systems & having regularly diagnosed the 24 volt system problems I'm far from being blind to JD 24 volt electrical systems & it quirks. Plus others that have replied to your thread are far from being blind to JD 24 volt systems.
Jim

 

[Bob]

(quoted from post at 11:01:43 08/17/19)

(quoted from post at 08:14:48 08/17/19) You probably will/should do the 12V thing but your problem might be
mechanical instead of electrical. Perhaps the splines on the armature
are not just right since that issue started with armature replacement.
Burs on flywheel but it wasn't doing it before?

I see where that could be an issue. I have 3 things that I really need explained. I think everyone is too blind with "24v is hell, and it sucks" to really give any other opinion.

My largest concern before going down the 12V route is that there is actually an electrical problem that *does not* go away magically by converting to 12V. Since no-one has really explained some of the symptoms other than by saying "12V is going to save you headaches".. I'm still wanting to get to the bottom of electrics before I do that.

I load tested both batteries with a tester, both test on the very high end of good, so, to my mind I do not have:

1) Melting battery posts.
2) A slow drain on the batteries due to dust in starter (which was rebuilt..).
3) With tractor idling, I do see batteries charging/haven't had any problems with batteries being low.


The one thing that I think negates mechanical/burrs on the flywheel is that the starter will continue to run, even if it has not engaged, until I unhook battery. Now, this could be the solenoid welding self closed, but, why would pulling voltage solve that? Turning key off and stopping depressing starter button have no effect.

I could see how the burrs could be a culprit if either the starter gear weren't able to find a smooth spot into the ring gear and would bang and miss and a few tries would get it into a lucky alignment.

I'm assuming both circuit breakers on the starter body are fine--what else goes bad in this path?

An oddity I note is that A battery POS should be grounded straight to frame--I can't figure out where that happens, it doesn't happen off the post/terminal.

The NEG is grounded through a fuse, which has blown several times while running though everything (3A).

" I think everyone is too blind with "24v is hell, and it sucks" to really give any other opinion. "

Not me, I enjoy working with these unique systems, and they can work very well with a little thought and understanding.


"An oddity I note is that A battery POS should be grounded straight to frame--I can't figure out where that happens, it doesn't happen off the post/terminal."

The common connection between the (-) post on the RH battery and the (+) post on the LH battery is connected to the chassis through the fuse or fusible link located at the RH battery.

Sounds like things on your tractor may have been swapped around a bit from the way it left the factory,which is shown in the diagram below.

Here's something to check... disconnect all wires from BOTH small terminals on the starter solenoid and check for continuity to the steel "frame" of the solenoid.

There should be NO continuity there, the solenoid coil MUST be isolated from the "frame"/housing of the solenoid.]

It's quite possible that it's the wrong solenoid for this (unique) application, or something inside is shorting, could even be an intermittent short in that area that happens only when the solenoid appears to "stick"


I just went back and read your post again, and noted that you had to open up the solenoid to unstick the contact disc, as others have said this can be a symptom of low voltage.

With low voltage there isn't as much magnetism to hold the contacts tightly together, and they will chatter, heat, burn and stick.

At this point, if the batteries are good and you feel that the cables and connections are good, I'd replace the solenoid, preferably with a NOS genuine Delco.

Besides low cranking voltage, the solenoid would be the prime culprit, IMHO.

 

[D-]

The fused wire connects to the positive post on the LH battery.
It would serve the same purpose if connected to the negative post
of the RH battery. (Earlier tractors had each battery grounded
individually.)
What this does is "splits" the system for the 12V lights (some are +
ground and others are - ground).
That fuse has no bearing on starting.

 

[BrotherJoe]

(quoted from post at 12:26:30 08/17/19)
Joe
i think after serving 13 yrs as a JD dealer service manager during the hey day of 24 volt systems & having regularly diagnosed the 24 volt system problems I'm far from being blind to JD 24 volt electrical systems & it quirks. Plus others that have replied to your thread are far from being blind to JD 24 volt systems.
Jim

Jim and others; I did not mean to imply that you folks didn't know what you were talking about, I was more frustrated with not being able to find and understand the problem prior to switching the tractor.

There is good news, however. After spending a saturday going through everything, I was truly stumped. Shop that rebuilt the starter called and wanted to know if things were working--when not, he wanted the starter back. He replaced the solenoid with a new one, and i ordered a 12V conversion to have in my back pocket.

Solenoid fixed it, but, I'm thinking of keeping the 12V conversion on the shelf for when this gives me fits again. As others have stated, there is one thing for certain about the 24V system--it is a bit difficult to debug given that it's actually relatively simple.

Fortunately for me, there weren't any additional accessories hanging off one leg or the other; it was all more or less stock, but, everything was also 50 year old cracked crusty wiring and connectors.

The final thing was pulling the starter from the tractor, but leaving connected and finding that it would continue to run. I had isolated 99% of the starter-system wiring and checked it for shorts and disconnected all of the additional lighting/switching.

 

[BrotherJoe]

Thanks Bob; ultimately I think this was it--it was certainly the solenoid, and, that is the one thing I did not get verified, is whether or not there was an internal short in the solenoid, but, based on behavior, I suspect thats what it was.

 

[Tx Jim]

BrotherJoe
Thanks for update. I'm glad you got your tractor's non starting problem solved.
Jim