John Deere 5420 lost power to dash and won't start

[201spencer]

I hope someone might point me in the right direction here. My 5420 was idling while I was out of the cab and shut off by itself. The problem seems electrical, the switch has no power, neither do the wipers, A.C. blower or turn signals. The headlights do work however which rules out any battery issues. I checked all the fuses which were fine and swapped some similar relays around which didn't help either. Could there be a fuses or breaker beneath the dash somewhere? Any ideas here? Thanks.

 

[Ken]

201 spencer Look for a sensor wire to be disconnected . I have a 4520 and under floor plate is sensor near clutch that is easy to be loosened by brush . runs fine until off the seat then dies and nothing is working.

Welcome to the forum.
ken

 

[201spencer]

Thanks Ken, I will look for that. Funny that it lost the electrical power to the dash while the tractor was idling but not in motion. Now even the wipers have no power?

 

[mddorange]

:welcome:
To the forum from Northwest Alabama.

 

[Ken]

Maybe recheck the ground of wiring also battery ground is clean and shiny.
Can see one failure to loose connection but more need to look at grounding.
How many hours does it have . sit outside in rain weather ?
ken

 

[skyhook]

Its pretty hard to say without a schematic but if your handy with a test light,
you could pull the ignition switch out and test for voltage at the pins, (be careful not to ground the test probe), with the key off, you should have voltage to one of the pins (for headlights and 4 way) although sometimes the headlights do not come on with the key off, but yours could be different.
Then, turn the ignition to "on" (not start) you should now have power to another pin on the ignition,
this will be for your wipers etc, etc...if you don't have power, your ignition could be burned.
This may happen when it's overloaded, as in when all the lights are on (at night) wipers going and heater etc, etc.
Usually ignition switches are rated at 40 amps, so if you overload them, they will burn out.
You may also have a "fusible link" that has burned.
Its really pretty difficult without a schematic to isolate these type of issues,
you seem to have checked all the obvious, good luck and let us know if you find the problem.

 

[201spencer]

Here is the update, I again check the fuses in the main fuse box and they were fine, removed the switch and found that the switch had no power coming to it. I back tracked the largest red wire to an inline fuse under the dash which was blown, replaced it and the tractor cranked but after a minute, blew the fuse again. Replaced it again and turned the key on without cracking to put power to the other 4 red wires but not the two green or two brown that are only hot when actually "cranking" the tractor. The fuse blew again which eliminated all but the 4 other red wires. Then I found that 2 of the four which are on a single switch lug were warm, bingo! I unplugged these two but the tractor now will turn over but not start so I think these two wires which are labeled 022A and 022B must lead to the fuel pump. Since the tractor will run until the fuse blows, I am hoping that the pump is OK and one of these wires has shorted out somewhere. Tomorrow I will somehow try to trace them down through the dash.

 

[sixdogs]

Excellent detective work.

 

[skyhook]

Sounds good, Spence....
You could remove those two wires (like you did) and run a wire from the positive on the battery,( a fused wire would be ideal)to the pump solenoid. This will tell you if the pump solenoid is shorted or not.
You could also remove one of those "two" wires (not the pump one) and do another test to determine if its the pump wire or the other one.