JD 3020 Diesel Light Problem

John Morrissey · Dec 13, 2009

We have a 3020 with the original 24V system. We have no lights on the tractor and cannot figure out why. All wires to the lights originate from the light switch however I cannot get continuity to chassi ground from any of the wires. Can anyone tell me how the lights get grounded.

buickanddeere · Dec 13, 2009

(quoted from post at 16:14:48 12/13/09) We have a 3020 with the original 24V system. We have no lights on the tractor and cannot figure out why. All wires to the lights originate from the light switch however I cannot get continuity to chassis ground from any of the wires. Can anyone tell me how the lights get grounded.

Without wiring diagram from 1-800-522-7448 it's not easy to explain.
Is the tie to chassis from between the batteries to chassis intact?
Who all has been tinkering with the electrics over the years?
The 24V system generator, regulator and starter make to reference to chassis.
The 12V systems are in two halves. One 12V + to chassis. Te other half 12V- to chassis.

rrlund · Dec 13, 2009

If they're like the 730Ds were,it's like B&D was eluding to,there's a ground wire between the batteries. On the 730s there were 4 sixes and the ground was hooked between the second and third. It just hooked to one terminal and went to the frame. You'd think it would have melted something or caused an explosion,but it had to be there for the lights to work. I would think if the 3020 used the same setup,they would have two twelves and the ground wire would be between the 2 batteries.

Ray · Dec 13, 2009

The fenders probably lost there ground.Try a test wire from the battery ground to the headlight bulbs and see if they light.

NY 986 · Dec 13, 2009

AMEN to that. 90% of any lighting problems on our 4010 diesel have been due to crud between the fenders and axle. We now have the lights directly grounded to the battery.

John Morrissey · Dec 13, 2009

Thanks for all the responses! I think grounding the lights to the battery would do the trick however I am still puzzled as to how they are supposed to work in the first place. I understand the + and - 12V system and how some of the lights operate off one while the remainder run off the other in order to balance the load off the batteries. Also the ground wire from the battery to the frame is in place.

There are two wires running to each of the lights, a power and a ground (I am assuming the black wire is the ground wire as it goes to all the lights). The power and ground wires originate at the switch. However, I have no continuity between the ground wire and the frame. If I run a jumper from ground to this this ground I have power to the lights.

So, I think I lost my connection from this ground wire to the frame. Does anybody know where this ground originates?

Buickanddeere, can I get a good wiring diagram at the # listed, the one I have is pretty fuzzy with not a lot of detail.

Anonymous-0 · Dec 13, 2009

JD parts book has a decent diagram. Also the Deere shop manual. The I&T diagram is a bad guess at the circuits, way too simplified.

There were at least four different wiring schemes in the '20 tractors, the earliest had no connectors, the latest were modular with many multiple wire connectors. You need the right vintage diagram or it will lead you astray.

Gerald J.

Anonymous-0 · Dec 13, 2009

I was told never turn the lights on any 24volt system when tractor is not running,the bubs are 12 volt and when the tractor is not running your giving the lights a full 24volts, and blows the lights quick. Check them to see if there blown.might be your problem, Rick

Anonymous-0 · Dec 13, 2009

That's not a problem with Deere 12/24 volt systems. Not a problem at all unless the ground wire at the middle of the battery circuit is broken and there aren't equal loads on both the + and - 12 volt sides.

Gerald J.

Tx Jim · Dec 14, 2009

(quoted from post at 19:19:07 12/13/09)

There are two wires running to each of the lights, a power and a ground (I am assuming the black wire is the ground wire as it goes to all the lights). The power and ground wires originate at the switch. However, I have no continuity between the ground wire and the frame. If I run a jumper from ground to this this ground I have power to the lights.

So, I think I lost my connection from this ground wire to the frame. Does anybody know where this ground originates?

Buickanddeere, can I get a good wiring diagram at the # listed, the one I have is pretty fuzzy with not a lot of detail.

The 800 phone # is JD's phone # to order manuals in which the tech manual will have a wiring diagram. A wiring diagram for a 4020 which will be close is on this site in the archives under a mans handle named Gwece

Finally no ground wire on factory wiring was on light switch. Ground only went through frame by way of the grounding wire on rear post to frame on LH battery

JD 3020 Diesel Light Problem

John Morrissey

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buickanddeere

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rrlund

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Ray

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NY 986

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John Morrissey

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Anonymous-0

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Anonymous-0

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Anonymous-0

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Tx Jim

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