JD 850 Not Starting

   / JD 850 Not Starting #1  

Sunspar2004

New member
Joined
Jul 26, 2011
Messages
4
Tractor
John Deere 850
I know there's been a lot of other threads about starting issues, but I think this is a little different.

I have a John Deere 850 that won't start at all--gears in neutral, PTO off, throttle in start, but nothing (dash lights don't even come on). Thought is was just a dead battery so hooked it up to a charger--lights come on but it just makes a clicking noise (starter I think). Interesting thing is, I took off the charger and tested the battery--voltage and everything checks out fine (but still no lights or starting without the charger on).

Any thoughts appreciated.
 
   / JD 850 Not Starting #2  
Since the lights come on with the charger on makes me think the battery is completely shot once they get that bad you cant hardly jump them even.

Out of curiosity how did you test it just by voltage or do you have a load tester BIG difference in the two!
 
   / JD 850 Not Starting #3  
X's 2 what Car Doc said.

I had the same thing happen on a JD 950, it was the battery. It wouldn't even take a 50 amp fast charger my neighbor brought over. Stole the battery out of my pickup and it started fine, neighbor said the "cells" where likely dead. He was a mechanic at our local IH dealer so I just took his word for it.
 
   / JD 850 Not Starting
  • Thread Starter
#4  
Car Doc: I just used a voltage meter/tester. Will try a different battery and see if that works.
 
   / JD 850 Not Starting #5  
Yeah thats what I would do volts and amps are totally different measurements and not something the average guy has knowledge or tools to measure.

A battery may well have 12.5 v etc surface charge but wont hold it under a load and thats what I think is going on. good luck

This is purely academic but nonetheless will mention it for future reference-

A poor boy load test if you wanted to do one ever in the future would be to attach your volt meter across the battery and try to crank the tractor etc the voltage should never go below about 9.5 v at the most and 10.5 is better yet and a sign of a good battery/starter system.

This will also test the connections so keep that in mind you are testing them also they are first in that circuit unless you can screw drywall screws into the posts themselves fwtw.

I bet yours will go to zero v guessing based on how your lights are working.
 
   / JD 850 Not Starting
  • Thread Starter
#6  
Follow Up: Tractor is back in action--new battery and around $80 to repair a few things on the starter fixed it (considering its never had any major work I'd say this wasn't bad at all to fix it). Thanks for all the posts.
 
 
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