Grimmchevy

lol I知 pulling my hair out on this one,and I知 bald
bought this tahoe for 2k with 150k original miles immaculate looking and just needed a water pump and starter. Towed it home and took me 2 hours to put new starter and water pump, go to crank it ( brand new yellow top optima) and no crank. This is my 7th Chevy I致e had 2x06 cateye silverados 5.3,1981 k10 350,93 tahoe/blazer,2018 silverado 5.3,and a traverse 2018. I知 very mechanically inclined and always done my own work, engine rebuilds,lifts,brakes,oil changes etc. but this one has me stumped. I checked all the relays all the fuses all the wiring. The only thing that I can tell so far is that there is a grounding issue in these years so I replaced all the grounds to my knowledge, and still no crank with my key in the on position also checked the starter switch. I am getting positive to everything, except for the 10 amp starter fuse under the hood, any idea on how to fix this the fuse is good but the test light shows nothing? I can manually jump the relay from 30 to 85 and it値l start over if the key is on.help!

mountainmanjoe

schematics are an absolute necessity anytime you're troubleshooting electrical problem. Your life will be very difficult without them
You can get em for free on charm.li


which one?
"CRANK"?
That fuse is fed by your ignition switch, so check there.

Yellow wire should go hot with key in start position.
Ignition switch gets power on red which comes from IGN fuses