Momentary electric loss while appling breaks

I have a 98 Honda passport. The last two weeks I noticed that once in a while when I apply my breaks my lights, radio, dash dims for a split second. It does not do it often. But it concerns me. Could it be some kind of relay going bad or something???? Batt and alternate was checked and terminals cleaned.

the battery could be going bad--the alt could be going bad--

also--for some reason the abs system could be engage momentarily. just my thoughts