3020D 24V Starter

[BrotherJoe]

Hi All!

My 3020 Diesel needed a starter. I was able to get a reman locally from a reputable source and I have the following symptoms that I'm puzzled by.

I got the starter put on, wired up, and connected R and L batteries back up and fired it up. Starter worked great; tractor fired right off. Shut down, re-started, started right up again; 3rd time tractor started up, but, starter continued spinning. Fortunately I had the RH battery loose still and was able to pull the terminal off and stop the starter and then killed the tractor. I checked everything over again, starter will spin (but solenoid does not engage) when I connect up battery.

I pulled the ignition button terminals, still, starter spins when batteries connected. Checked all wiring over again, not sure whats up, still.

Pulled starter off again.

On the bench I an fire the solenoid independently by getting to the 2 small terminals on the back as you'd expect, can spin the starter independently from the 2 large terminals on the starter (eg: not through the solenoid).

I'm puzzled as to why on the tractor it's wanting to spin when terminals are connected. What am I overlooking?

Thanks,

J

 

[Tx Jim]

Sounds as starter solenoid failed or battery voltages are low. Check each battery voltage & report voltage of each.

 

[BrotherJoe]

Thanks, Jim.

Right battery is 12.95 left battery is 13 volts.

I tested hooking the solenoid and starter upb the way it would be on the tractor and then firing the solenoid and it all seems okay.

If I hook negative up to the negative post on the solenoid and I hook positive up to the positive post on the starter and then I take the outer small terminal on the solenoid to ground the solenoid fires. The gear comes out and the starter spins.

J

 

[BrotherJoe]

Hmmm. There are two regulators. I think the brown wire from the loom goes to the small terminal on the back of the solenoid (inner).

I had it on the S terminal where the safety switches end.

J

 

[Tx Jim]

Technically there is no ground wire associated with the starting/generating/regulating circuits on a JD 24 volt electrical system. Yes there is a ground wire utilized on 12 volt lights & accessories.

 

[55 50 Ron]

Hmmm. There are two regulators. I think the brown wire from the loom goes to the small terminal on the back of the solenoid (inner).

I had it on the S terminal where the safety switches end.

Are you saying it now is working correctly?? I'm curious when you said "Hmmm. There are two regulators." I have experience with a 730 diesel (1959) and I only see one regulator on it. Did the New Generation tractors have two regulators??

 

[BrotherJoe]

I didn't know for sure until I did some searching. The wiring diagram that I have for a 3020 diesel only shows a single regulator, however, it appears at some point there was an updated loom for the 3020 that added a second regulator. I don't have that diagram though; maybe someone else does. Mine, apparently, was updated at some point it its life.

An odd thing is that the left battery has a fuse from positive to chassis, which I think was part of the updated wiring? However, it's blown (and keeps blowing) and I think it's supposed to be a slow-blow; I don't have any on hand. Interestingly, I put everything back again (except the evil 3rd bolt) and tested it and all was well--but..that fuse blew and then the starter stuck "on".. I wacked the solenoid with a screwdriver handle and it let go. I wonder if those events are related. But, I *think* things are mostly OK, except for the lights not all working because of that fuse.

Does anyone have a link to the updated wiring loom diagram for the 3020?

I haven't put the evil bolt on the backside of the starter in yet, but, I'm getting good at it!

J

 

[BrotherJoe]

I don't know. The wiring diagram that I have for a 3020 diesel only shows a single regulator.

Technically there is no ground wire associated with the starting/generating/regulating circuits on a JD 24 volt electrical system. Yes there is a ground wire utilized on 12 volt lights & accessories.

Tx Jim: what causes the solenoid to stick with low batteries? Does it chatter and then basically welds itself because it's arcing over rather than making a fast, clean, connection?

J

 

[Tx Jim]

Your explanation of why washer inside solenoid cap sticks to studs due to low battery voltage is the way it was explained to me many yrs ago. No JD 3020 left factory with 2 voltage regulators. The reason the fuse blows on LH rear battery + connection to frame is there is a short to tractor frame on one or both the accessory circuits. https://partscatalog.deere.com/jdrc/sidebyside/equipment/8094/referrer/navigation/pgId/1799069

 

[BrotherJoe]

Your explanation of why washer inside solenoid cap sticks to studs due to low battery voltage is the way it was explained to me many yrs ago. No JD 3020 left factory with 2 voltage regulators. The reason the fuse blows on LH rear battery + connection to frame is there is a short to tractor frame on one or both the accessory circuits. https://partscatalog.deere.com/jdrc/sidebyside/equipment/8094/referrer/navigation/pgId/1799069

Thanks Jim,

I'll do some more poking for the short;

 

[rrlund]

I just had the exact same thing happen with a new rebuilt on my Ford pickup. Took it back and got another one. Second one worked.

 

[Tx Jim]

Thanks Jim,

I'll do some more poking for the short;

You're welcome

 

[miangus]

Low voltage creates high amps which may cause the contacts to weld. I would replace the solenoid or disassemble and check the contacts. Once they weld the contact is compromised. I am assuming that when the starter was rebuilt the rebuilder installed a new one.