I have a 1998 k2500 with a 7.4 L vortex. Battery went dead, when I repaced it the truck turned over but wont start. The gauges wont work or any of the door locks or windows. could this be a ECM or key switch?
any suggestions?

 

Does it have factory security system? If so, need to do a security relearn.

 

I assume you have checked all the fuses. Also make sure that you hooked up both positive wires...there should be 2 to connect to the battery.