5420 instrument cluster

[traded]

I'm having trouble with my instrument cluster and do not want to have to replace. The fuel gauge registers as either full or bounces when it gets to a 1/4 tank, the temp gauge pegs when working(replaced sensor) temp is in operating range, tested with a temp gun. Tachometer reads when lights are off, but when they are on it bounces all over the place. I'm hoping a possible ground issue, but I do not have a wiring diagram so diagnosing blindly. Is this a common occurrence, as John Deere and they suggested to replace the cluster.

 

[Zebrafive]

It does sound like ground issue. JD uses black wire color for ground. Also pins for the connector on the circuit board of the cluster may need resoldering, the solder joints can crack.

 

[traded]

Thx, hopefully I can tackle it this weekend.