Im putting a 96 Z28 together, everything works but the horn,dome light and rearview lights......I checked the fuse in the engine bay for the horn. it is good and has 12v going to it. I tested the horn with a jumper wire and it works. I also checked the interior bulbs, they're good.

 

if you have 12v goin to the horn,....and the horn tested good,....has to be ground?

 

it's not the ground, if I run a jumper wire to them they'll work......I guess I need to locate the horn relay and start from there