No Heat

97 Ram 2500 I have no heat I flushed the system but that did nothing..whats next??

I dont know the late stuff but I would find the valve (vacuum or cable controlled) that controls the coolant flow & see if it's open or shut. then if the right doors are open/closed to direct air thru the heater core.

Seems that the diverter door has been a problem for a lot of pepolpe here. You'd do better asking on the truck forum here.