Instrument panel ground on CTL80/Takeuchi TL150

I have a Gehl CTL80. all Of a sudden the instrument cluster quit working. Everything run fine just not gauges. I think it is a grounding issue. Does anyone know where the ground location for the instrument cluster is located?
the reason , I think it is a ground problem , is the horn will not honk when the button is pushed. the horn circuit is hot and when the horn button is pushed it connect to ground and would honk. the hot side is ok. I don't really care about the horn, but suspect the...

Instrument panel ground on CTL80/Takeuchi TL150

Instrument panel ground on CTL80/Takeuchi TL150