On my 55K mile,1992 D250,it would seen the sporadic frequent "on and off" workings of the: radio,signals,heater fan,etc. could be related to the weak OEM grounds.
I'm thinking a heavier gauge cable from the battery to the block,to the frame and to the cab.
Any suggestions/can someone recommend a more detailed/direct grounding area in the cab related to the workings of the accesssories?
Thank You.