headlight relay

The headlights in my 2003 TJ won't come on, but the high beams will. With the multi-function switch in the headlight position both the tail lights and dashboard light up so I don't think it's a switch issue. I know that's a common problem, but I'm not sure replacing the switch should be plan A...

I have a headlight harness that I used in my TJ prior to switching tho LED headlights. It is plug and play with these connections: One wire to battery positive One wire to ground One connector to each headlight One connector to factory headlight wire connector to act as trigger I will part...