Oil Pressure Alarm

I have a 7200.  During the winter I had my dealer work on it, transmission issues and a wiring harness because mine was dry rotated an cracked and shorting out the switch that operates the PTO shaft.  Most of the instrument panel didn't work at various time.  Long story, but, the general manager had his guys build an new harness for it. instead of purchasing one for 1700.00.   It has worked great until today.  Oil pressure alarm would come on and go off.  I was in a very rough field.  The oil is new in the tractor, and full.   Could I have a short?  Where do I look?  What color wire?  

I would think it could be a loose wire at either end possibly.  Any help would be appreciated, really need to be baling not put it back in the shop.  

 

Thanks 

Scott 

 

Oil Pressure Alarm