Help: JD 6920 electrical issue:

[Hummin-Cummins]

John deere 6920 auto pwr command arm,

blowing the fuse for pto 4wd and difflock

have checked switches under mudguards, looms to relevant solenoids etc

also checked loom in cab behind r/h cab pillar but to no avail.

Any help or suggestions would be much appreciated as im about stumped for what to do next.

TIA
H-C

 

[john432]

Have you checked the ohm reading of the coils of the solenoid s themselves. Just in case there is s short circuit of the coils and the power going to the earth chassis.

 

[Hummin-Cummins]

Have you checked the ohm reading of the coils of the solenoid s themselves. Just in case there is s short circuit of the coils and the power going to the earth chassis.

I’ve got them all unplugged and its still blows the fuse

 

[john432]

So guess by checking the loom you've tested each wire of the offending circuit s for a leak to earth?

 

[agcoparts]

you have a short to ground in the wires..

 

[Hummin-Cummins]

So guess by checking the loom you've tested each wire of the offending circuit s for a leak to earth?

Nothing going to earth solenoid side of the circuits, looks like Its possibly a direct short in the cab somewhere but I can’t find it for love nor money

 

[NZ Tech]

Have you disconnected the transmission harness from the righthand rear corner of the cab under the plastic cover.

Might make diagnostics of it easier.

Also could be a rubbed wire behind the righthand cab corner post. I usually run them around the front side if they need repairing. So cut and repair and join.

 

[Timbo]

I’ve got them all unplugged and its still blows the fuse

So youve got a rubbed wire

 

[milkloss]

Old thread but I’ve got trouble too.

6920 clicked out of shuttle up the road with plenty of random warning lights. Would go into drive to get the last 1/4 mile but kept going into neutral every 10 seconds or so, so I nursed it along.
Found a fuse had blown behind the seat, circled in blue:

Loaded the straw and decided I’d drive home if it didn’t give trouble but the fuse blew on the last bale and then blew another one as soon as it was replaced and key on.

I’m guessing I need to get behind the rear pillar but I have to load all my tools and relevant gear in the truck to go and sort it.
Any tips and method of removing said pillar trim I would be grateful for.

 

[milkloss]

Ok so I’m in there, followed the offending wire to the corner post..... it’s the orange menagerie and combined with about a dozen others back to fuse board and maybe three go round the corner post. All I get is a sizzle for a few seconds before the fuse blows but I can ID the noise at the post.

It’s so flaming tight there....... mr JD was having a very bad day when they stuffed that lot in there that’s for sure.

console off to get to the other side I guess?

 

[Phil P]

Ok so I’m in there, followed the offending wire to the corner post..... it’s the orange menagerie and combined with about a dozen others back to fuse board and maybe three go round the corner post. All I get is a sizzle for a few seconds before the fuse blows but I can ID the noise at the post.

It’s so flaming tight there....... mr JD was having a very bad day when they stuffed that lot in there that’s for sure.

console off to get to the other side I guess?

It will be rubbed through on the back corner of the post -

you’ll need to remove as much of the panels on the r/h console as you can and unplug some stuff to try and free up enough cable to get to the shorted cable. Some of the cables run right through to the dash so it’s can be quite a big job to get enough slack.
If your desperate for the tractor push some rubber between the post and the loom, this is only a temporary fix though. However it’s worth put some insulation there after it’s fixed to stop it happening again.

 

[milkloss]

It will be rubbed through on the back corner of the post -

you’ll need to remove as much of the panels on the r/h console as you can and unplug some stuff to try and free up enough cable to get to the shorted cable. Some of the cables run right through to the dash so it’s can be quite a big job to get enough slack.
If your desperate for the tractor push some rubber between the post and the loom, this is only a temporary fix though. However it’s worth put some insulation there after it’s fixed to stop it happening again.

Appreciated. they seem to have rubbed through at the back and not the post. I’ve managed to snatch 3/4 inch up so I can see the 3 wires the 10 or so turn into. Might wedge some plastic behind and push them back till I get home.

Don’t fancy it popping out of gear on the 9mph long draw uphill with lots of traffic behind

 

[Tractortech]

Now Then..
I usually identify the damaged wire/wires at each side of the cab post. Then snip them each side and solder some new 3 or even 7 core in with heat shrink over the joints..

 

[Combine Rescue]

Yes. Solder and use self adhesive shrink.
They will seal the joint ant prevent copper corrode along the cable. Don't use cripms unless you not good with solder iron but then use the one with self adhesive heat shrink.
Unless you do like to repeat the job next year.
You can find some YouTube tutorials how to join and seal two cables.
Or ask for help.
Some times DIY is Don't Involve Yourself

 

[milkloss]

Thanks chaps. Had to leave it behind as it got a bit late for hauling straw, I’ll get a lift down today and grab it.
I’m ok with an iron so should be good when I can get in there. If I can trace the wires I’ll snip and pull them through the console, solder and then stuff back round and solder again past the hitch release handle. I can’t believe how tight that loom is just on that corner...... major error really. Even the wires out the back of the fuse box have nearly rubbed though on the rear bulkhead...... at least it’s plastic I suppose. I might leave them loosely bundled but protected with a roll of squished conduit stuffed round the corner.

 

[Brady]

Was it the wires rubbed on the post

 

[milkloss]

Was it the wires rubbed on the post

Yes, it was. I got it home with plastic wedged either side and had a solder up when I got home. To be honest it was so tight I never found the offending wire but rerouting the orange set round the front of the post solved the issue.

 

[Steven12]

well how’s things having similar problems with a 6620 melting relays and lately the headlights and front corner light have given up altogether any ideas ?

 

[Asnordfjell]

well how’s things having similar problems with a 6620 melting relays and lately the headlights and front corner light have given up altogether any ideas ?

Did you find any solution? Mine went all blact yesterday, lost all lights, lost drive and control over the hydrauliks. Engine runing and was able to stop and start for a bit but the all went offline