Hi Matthew, with Chuck and Hank you already have two of the best electrical folks in the world helping but looking at my tech manual, the TDCM is not involved in this problem as Hank mentions. The pink wire runs from key switch to TDC module but then just uses that as common terminal to tie up with the purple wire running to PTO switch. You'd better check your connections to see if something is corroded or loose as the pink/purple have to be at same potential unless something is loose.