Hi guys...i'm back alot quicker than i thought i'd be....the wife came home the other day,no tail lights no dash lights,i've read this was due to a bad ground....are these two circuts sharing a ground?..i got power everywhere else...just swapped out the fuel sending unit...new pump/relay ...the works...
'96 chevy 2500 xc
40 series flowmaster...24 in" of 3" straight pipe
5.0 engine
high flow cold air intake
D.D.

 

did the lights work before you replaced all that stuff? Also just because you have power, doesnt mean you have a complete circuit. By looking at the wiring diagram, it looks like the ground for the fuel pump relay, and your shift indicator lights, share the same ground. Says the ground is near the thermostat housing.