3120 display jumbled, no start

   / 3120 display jumbled, no start #1  

kensington-keller

New member
Joined
May 29, 2023
Messages
3
Tractor
John Deere 3120
My deere batter was dying pretty consistently. I would charge it or jump start it. The other day I couldn't even jump it so I was messing around and I put 12v directly to the starter and negative to a frame bolt. Didnt get anything. I later read in the manual that this is a bad move.
First the relays were clicking and the gauges were dancing. I pulled some relays and tried again. I got some codes. And now I have this.

Is the computer fried?
20230529_182328.jpg
 
   / 3120 display jumbled, no start #2  
If it was my tractor I would get a new or known good battery. Disconnect positive lead and ground for 10 minutes. Touch positive lead to ground cable to dissipate any partial stored voltage. Then connect to the known good battery. Voltage of less than 12v can do some weird things to relays, ecm, and digital dashes. Usually shedding the low voltage and providing 12.6 volts will straighten things out.
 
   / 3120 display jumbled, no start
  • Thread Starter
#3  
Okay thanks Rusty, I was measuring strange voltages at the fuses and relays, like 6V, even when I had a charger hooked up providing something like 12.6V.
Ill give a new battery a try. The battery was a genuine John Deere and it died after a year, so im wondering if i have a chaffed wire shorting to ground.

Appreciate the help
 
   / 3120 display jumbled, no start
  • Thread Starter
#4  
@RustyA that did it man, display is back to normal and she starts right up.

Thanks for the help
 
 
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