John Deere 4320 Dash Issue

[minnesotafarmer]

I have a 2007 John Deere 4320. When I turn the key to the run position, the dash does not power up normally. The only lights that come on are the indicator light for the glow plugs and the trouble light. The digital display is garbled and will not display a trouble code. This problem has been intermitent and seems to go away if the battery is disconnected or the ignition is unplugged for a period of time, maybe a day. I have installed a new battery and checked the voltage coming into the ignition switch and it is 12.9 volts. I have also taken the ignition switch to the dealer and it tests fine. I was wondering if anyone has had this issue or would be able to help. Thanks.

 

[Ken]

Welcome to the forum.
I have a 4520 year 2008 and some times the plug going to the ignition switch will partly come loose giving weird lights. Maybe recheck all the plugs and connector under dash.

What ever you find leave a note its fixed may help some one else with problem.

ken

 

[minnesotafarmer]

Update: The tractor is now at the point where only the glow plug indicator and the trouble light come on and the remainder of the dash does nothing. I have taken the cowling off to expose the dash and all of the wiring and cannot find any issues. Anyone have any ideas? Thanks.

 

[Ken]

Update: The tractor is now at the point where only the glow plug indicator and the trouble light come on and the remainder of the dash does nothing. I have taken the cowling off to expose the dash and all of the wiring and cannot find any issues. Anyone have any ideas? Thanks.

Do you have a volt meter and experamce to read different dc voltages?
My Repair manual has a Theory of operation and explains how the dash reads the different voltages.

Do you have lights , tail lights or work lights. ? these are not going in or out of the dash panel but would give you idea if there is voltage from the battery.
The next check is power to fuse key switch on should be power to dash with red wire X10 connector terminal D 122E H 122D Red wire switched voltage. at Terminal562C Red this is power to operate the display panel.
Then explains the operation with a IF - THEN procedure to check or test the panel.
And continues about 50 pages of tests.
So if you have the listed voltages still doesn't work suggest a repair Manuel from J.D. worth every $ it costs

ken