1999 Chevy Silverado Instrument panel lights are out. Truck

Hi, I hope someone can help with this. I've had to reset the computer by taking out the ecm fuse and putting it back in several times over the last couple of weeks for my truck to start. Now that won't work anymore and my instrument panel lights aren't on and fuel pump isnt humming.
I've checked all fuses and relays and they all seem to be fine with the exception of the relays down by the steering column. Not sure what these are for but one of the small ones look like it may be bad.
Is it possible that the lead wire from the battery to the fuse box might be to corroded? I've had to change the wire from the battery to the starter because of this. The wire looks ok to me but cant see inside the shield to make sure.