97 Maxima lights dim, radio turns off

Hi everyone. I have a problem. My car wouldn't start, got a new battery, new alternator, and had a fusible link replaced. The car started after that. Now when I turn on the headlights and the brights, the radio turns off and the a/c slows down. The interior lights dim also. What could it be?

Can anyone help, please? The mechanic couldn't find anything wrong.

the alternator is the only thing that pops in my head, but you said you had that replaced.

We replace the alternator twice actually. We thought the first one was bad so we returned it. The mechanic said the alternator is giving power, but somehow it's not reaching the battery or something.

Sounds as if you have some sort of short or open relay that is draining the battery at all times. Those are the biggest pain in the ass to find. Short of taking it to a dealer who can hook it up and check for bad relays or a short somewhere in the wiring harness I don't know what to tell you other than good luck. If the alternator and battery have already been replaced then an open circuit is definately the next step.