[Man-o-war]

When I turn key to ACC, Engine Warning light comes on and goes off after few sec, Wait To Start light comes on and goes off after few sec, gauges start to cycle but when tach reaches approx 1/3 rotation around 1200rpm mark, loud click is heard from ECM and dash resets to 0. If I keep key in ACC position, it keeps doing this over and over. When I turn it to start, nothing happens. Tried disconnecting batteries for a few, no change.

Truck is rollback 5sp Spicer 300k

Any ideas where to look? Thanks guys

 

[Man-o-war]

By cycle I mean sweep the needles all at the same time....to clarify