Installed trailer wiring ....... Blackout!!

[Biggin0822]

The trailer lights wiring had the ground wire cut off so I re-grounded it and hooked up the trailer lights and went to start the truck and acted like it had a dead battery. Battery voltage tested at 12.6v. No fuses blown. I put in a new ignition switch and..... nothing. The wiring is a mess in this 1985 c10 2wd auto with a 350. Originally had a 305. I ordered a new painless wiring harness but Im really curious what happened here.

 

[gpmorgan]

Did you test your starter?

 

[Biggin0822]

I didn't test starter. Would that make a total blackout? I don't get power to anything.

 

[gpmorgan]

Sounds like possible battery connection coroded. Positive cable at starter loose???