John Deere 4600 won't start - bad battery cable

TreePointer · Apr 4, 2012

Last year, our 1999 JD 4600 wouldn't start. It had a weak start or two, then only heard a solenoid click, and finally got nothing at the turn of the key.

Battery tested okay, had good voltage in both battery cables, alternator seemed okay, got good voltage across the starter, fuses and relays were fine, and I even replaced the thermistor. A JD tech took a look at it on site and wasn't sure at first. After a while, he concluded the positive battery cable had been corroded on the inside. A replacement got it running again for over a whole year.

Fast forward to a couple days ago, the tractor decided not to start about a quarter mile from the barn. I test most of the same things again and even swap out the positive cable--still no start and now I'm getting worried. I swapped out the negatibe/ground cable and that got it running again.

So what is the deal with tractor battery cables? These two bad cables were original JD cables from 1999, so it took about twelve years for them to go bad Do they just go after so many hours? Do tractors need a special type of battery cable? Is this issue common across many makes & models? Do you find you need to replace these cables very often?

One thing that we started doing over he past two years is using a rear PTO snowblower. The snow sometimes blows back onto the tractor and coats it. Maybe this accelerated battery cable degradation?

beenthere · Apr 4, 2012

I've got a '98 4300, and no problem with cables....yet.

But I don't find 13 years "very often" for doing some repairs. May have been some aggravating conditions over the years, and the battery passing off gas may have contributed. Hard to say.

How many batteries in those 13 years?

TreePointer · Apr 4, 2012

This 4600 really has been babied. When not in use, it's been stored in a barn with a concrete floor and only has 475 hours on it. It's on it's third battery, but really it only needed two because I replaced the battery last year when I had the first battery cable issue. The guy who tested the old battery said that he couldn't find anything wrong with it, but I replaced it anyway out of frustration. This latest battery has been tested and fully charged.

Sorry about using the term "very often." I'm wondering if there are folks out there who replace these cables every year or every couple years when used in very wet or corrosive conditions (like around salted winter roads). I'd also like to know if there is a specific type of cable that is better for tractors and other similar machines (bulldozers, skidders, backhoes, etc.).

Oldtractorfixer · Apr 4, 2012

Not sure of the reason but it happens occasionally. Just had the same problem on our 2005 Landini. Battery connection was a little corroded. cleaned, helped for a week or two then one day it would start the next it wouldn't. After I chased down that it had to be a bad connection at the battery I cut the insulation off at the terminal and you could see the corrosion. Are you plowing snow that might have gotten some road chemicals in it? Some of the new stuff they are using is wicked. It is a big problem with highway trucks. If they get a break in the insulation on the wiring it will corrode inside the wire for 5 or 6 feet. Trailers that are one or two years old with major wiring problems in some areas.

TreePointer · Apr 29, 2012

Follow up:

I finally got around to stripping the insulation off the bad ground cable. The copper strands look beautiful in the middle but the ends show discoloration/oxidation: Apparently it was enough to affect the current.

30" 4 AWG cable:

Cable terminal not sealed like today's cables:

Middle looks good:

Oxidation at battery terminal end:

Oxidation at other end:

Thanks to all for your input!

megaboz · Apr 30, 2012

Really doesn't look too bad. But a good high quality battery cable should resolve the issues.

I know from personal experience that it is usually the contact point that causes the problem. Not enough surface area and a little dirt is a real problem.

Now from a personal preference I do not like compression (crimp) style cables. I tend to make my own and fill the terminal end with solder and then shove the end of the wire in and then let it cool. Put heat shrink around it call it done.

TreePointer · Apr 30, 2012

Yeah, it's deceiving. It doesn't look too bad, continuity is good, voltage across it is good, but current is not so good.

AGGIE00 · Apr 30, 2012

Are you saying it won't crank or won't fire? I have the same tractor 99 4600, and after the second fuel shutoff solenoid at $180.00 each I found the problem which was the thermostor. A $3.00 electric part soldered in behind the fuse panel. Problem solved.

TreePointer · May 1, 2012

AGGIE00 said:
Are you saying it won't crank or won't fire? I have the same tractor 99 4600, and after the second fuel shutoff solenoid at $180.00 each I found the problem which was the thermostor. A $3.00 electric part soldered in behind the fuse panel. Problem solved.

Both. More details:

When this problem first came up a year ago, I noticed one slower crank, but it still started. Next time I attempted a start, the starter would click, but no crank. Finally I got nothing. After a couple days of checking continuity and voltage in all cables, checking battery, starter, alternator, cutoff switch, all fuses and relays, and even replaced the thermistor, I decided to contact the dealer. A JD technician came out and also checked everything--he was stumped. They took it back to the dealer and the culprit was a bad positive battery cable. Cable replaced. Worked just fine.

Fast forward to a month ago and the tractor had been running perfectly. Then, it had a slightly slower crank, but it started. The next day, I was about 300 yards from the barn and stopped the tractor to check a fence. I went to start it and got starter clicks and a slow crank, but no start. Turn the key again and just get starter clicks. Turn the key one more time and just get a solenoid click. Pulled the battery and gave it a good overnight charge and had the battery shop down the road test it--it was good. I reinstalled the battery and got nothing--not even a single click. I tested voltages across all relevant components, and also found that the fuses and relays were good. I thought that maybe the new positive battery cable from last year went bad after another season of snow blowing. I replaced it , but the tractor was still dead--not even a solenoid click.

FINALLY, I did some reading on a forum and learned that having a bad ground or ground cable can also cause this. Someone recommended making a parallel jumper cable connection. (That is, leave the ground cable connected to the neg battery terminal and the other end attached to the ground bolt. Next, take a good quality jumper cable and make that same connection from the neg terminal to the ground bolt on the engine.) I tried it, and it immediately started with a loud solenoid "thwack," strong crank and fire! Yeehaw!