No running lights, interior or dash lights.

Check your grounds really good i fought a similar problem with my 85 ram I took me months to find it but it was the ground on drivers side frame right behind the rear wheel. It went to the drivers side taillight. But it jacked my whole wiring up. My brakelights would work unless the headlights where on and if they where on the taillights wouldn't nore would the brake or turn signals it was crazy took me forever to find it I hope this helps save you some stress.