2955 electrical problem

jm42

Member
Ok, back at it. Left dash Assy should have five lights come on when key is turned on. This will not happen. All other functions of the tractor work.
Replaced and or refurbished all the circuit boards now, all fuses are good and grounds tested and an additional ground added. Still cannot get these
lights to come on. Also fuel gauge is not working and cannot get power to fuel sending unit. Light bulbs are also good. The 4x4 light, park brake and
bright light indicators do light up when activated and temp gauge works. There are three brown wires attached to the circuit board at the bottom that
could be In the wrong place not sure, I recently purchased this tractor thinking this would be easy fix. Any help is appreciated, thanks
 
first thing you need to find is a wiring diagram now when i first went to work for the local deere dealer thy was a major up date on the 55 series cab tractor on the electrical wiring in the dash a extra starter solenoid under the hood and some wires moved around under dash this was done as thy had a problem of self starting deere gave 4hrs labor to do the job seem i did like 80 or 90 of then in my dealers area.. that was like 25 plus years ago .. so the wiring diagram needs to show the up date to
 
Wish I could see the wiring diagram...

But without it, just general information.

Typically there will be a common power source to the 5 lights and the fuel gauge. Find the break in that power source and likely all will start working.

The fuel sending unit gets it's power through the gauge. Don't expect full voltage at the sending unit, only a small signal that comes through the gauge.

If these are warning or indicator lights, they will have power to one side of the lamp, the ground will be made whenever the lamp is supposed to be on.

Again, this is just typical design, without seeing the wiring diagram it's just a guess.
 
I had all kinds of dashboard related problems on my 2755. The pins in the wire connectors are tiny and very fragile. I very carefully recorded where every wire went and what color it was. I then un-soldered the pin connectors (square thingies), and replaced them with pig tails with GM Weatherpack connectors about 6" from the boards. I arranged them to where it would be impossible to hook them together wrong next time the dash panels had to come out. I replaced the other square connector thingies on the harness with the appropriate connectors.

It took a couple of hours, but I have no problems any more.

You do that and all those goofy problems go away.
 
I am not savy with the diagrams but I think the issue is related to the ground side of the lights. I am trying find someone local to help me understand what turns on the ground to the lights when the key is turned on. Thanks for your help. The lights have power and when I manually ground them they come on. You helped me understand that the ground for these lights gets tuned on.
 
What do the lights indicate?

Are they each assigned a purpose, to tell something is on, or in position, or at fault?

If so each light will have a separate ground that is activated by whatever function the light indicates. Chances are not all the grounds failed at once. If you check at each lamp, and have voltage on both sides of the lamp, then for whatever reason that lamp is not receiving it's ground signal. If both sides of the lamp are dead, the circuit (probably a common circuit that feeds the 5 lamps and the fuel gauge) is dead, probably a broken solder connection, bad connection, fuse.

If they are instrument illumination lamps, they should have power to one side any time the ignition (or possible the lights) is on, ground to the other side at al times.

Again, these are just typical instrument wiring examples, go by the diagram, not my ramblings!
 
These have specific functions like air filter, battery etc. they come on when key is first turned on then go out after started. Only other time they should come on is if a malfunction occurs. They have power but do not come on. I am thinking the ground to this circuit is not working. I have a tech trying to locate the ground activation.
 

Until someone picks their way along the circuit board and wiring to find where there is voltage then at the next point there is no voltage where there is supposed to be voltage . And find where there is no voltage with relation to "ground" then at the next point there is voltage where there is not supposed to be voltage
 
(quoted from post at 10:46:15 05/21/20) I have a tech trying to locate the ground activation.

There's nothing but a bad/loose ground connection can cause ground to loose continuity IE no switch is involved with ground on warning lights.
 
If there is voltage to those 5 sensors don't worry about if the lites come on when you turn on the switch. The sensors will still work and warn you if something is wrong. Try grounding one of those sensors and see if the lite comes on.kk((
 
I grounded several and they come on. Fuel gauge must be the sending unit? I am just kind of nuts about things working but i am about to raise the white flag. So far all circuits are checking good. Thanks
 
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