Dodge Repair: dash cluster/computer problems, dodge ram 1500, mud and rain

Question
98 Dodge Ram 1500 2 door 318. Went 4 wheeling in mud and rain, computer went out. replaced and worked for 10 miles but sluggish and went out again. Tried 2nd new computer and NOTHING! Dash instruments will not work. Truck turns over but no start, no instruments. Checked through and through with diagnostics, wiring diagram, etc.
ANY IDEAS? We're stuck and desperate?

Answer
u have something shorting out the computer in same way  recheck all the stuff that is tied into the computer  sorry i cant give any better because u did stufflike muding and well that will cause stuff like u have now  and with out looking at it for myself  not much i can say.