JD 4020 light switch issue

[MaverickM23]

Early JD 4020 diesel 24 volt, I rewired this entire tractor 2 years ago and everything has worked perfect until last night. Was picking corn and turned on the lights to the first position which should be all on but the outer two on the fenders were super bright but the inner two and the rear were dim and only measured 6 volts. Switch to the next position and all fender lights are bright but no back light, switch to the third position and all lights go out. I'm thinking its a switch issue but curious to see what others thought. Other weird thing is when I turn the key to on the gen light comes on but not the oil light but when I switch the light switch to the first position the oil light glows bright, this is all without starting the tractor. The lights and all gauges had worked perfect until now. Any ideas? Thanks

 

[wore out]

Early JD 4020 diesel 24 volt, I rewired this entire tractor 2 years ago and everything has worked perfect until last night. Was picking corn and turned on the lights to the first position which should be all on but the outer two on the fenders were super bright but the inner two and the rear were dim and only measured 6 volts. Switch to the next position and all fender lights are bright but no back light, switch to the third position and all lights go out. I'm thinking its a switch issue but curious to see what others thought. Other weird thing is when I turn the key to on the gen light comes on but not the oil light but when I switch the light switch to the first position the oil light glows bright, this is all without starting the tractor. The lights and all gauges had worked perfect until now. Any ideas? Thanks

Your wire, fuse or fusible link that connects the midpoint of the two batteries to the chassis is "blown" or you have otherwise lost continuity there.

As it left the factory, one end attached to the (-) terminal of the LH battery, the other to the battery box/chassis.

 

[Tx Jim]

Ditto what wore out stated to check accessory ground wire from LH rear battery post to frame

 

[MaverickM23]

Ditto what wore out stated to check accessory ground wire from LH rear battery post to frame

Alright that's what I will check out when I get home tonight, thanks for the quick help

 

[MaverickM23]

Your wire, fuse or fusible link that connects the midpoint of the two batteries to the chassis is "blown" or you have otherwise lost continuity there.

As it left the factory, one end attached to the (-) terminal of the LH battery, the other to the battery box/chassis.

You were right on, the battery terminal was all corroded and not making a connection, cleaned it up and now everything is back to working. On another note what do you guys do to prevent these 3ET batteries from corroding? These batteries are only 4 years old and make a mess all around the terminals. They are Deka batteries and they do it on every tractor I have.

 

[wore out]

You were right on, the battery terminal was all corroded and not making a connection, cleaned it up and now everything is back to working. On another note what do you guys do to prevent these 3ET batteries from corroding? These batteries are only 4 years old and make a mess all around the terminals. They are Deka batteries and they do it on every tractor I have.

Keep the tops of the batteries washed off and CLEAN. I insert a piece of plastic sheet between the battery and the steel box, on the side where the terminals are to prevent current drain if some dirt/moisture/acid does build up there.

Also, I have been using a shot of "Fluid Film" on battery terminals for several years, I've never seen it recommended for that purpose, but it has worked well for me.