1989 Chevy Astro Headlights do not work

My headlights all of a sudden went out on me and I can not find what is wrong. I replaced the switch with no luck. All other electrical is working fine. There is power at the switch but no power at the headlight plug. I used an ohm meter to check ground at the headlight plug but it seems that there is none. I've read that there is a circuit breaker, a relay and also a fusible link but the repair manual does not say where they are. I also noticed that even if I try the high beams, the indicator light does not come on. Here's a picture that someone told me were the fusible links but how do you check them and which one is for the headlights? I'm at a loss on what to do.