96 XJ here. About a year ago I installed an aftermarket 55/100 headlight wiring harness from SMC Truck...



...and just now both my low beams went out. High beams are still working though.

I don't think it's any grounding problem at the headlights as each side is ground individually and, like before, the highs still work.

Where should I begin testing?

I assume the fuse is still good, and that maybe the problem is at one of the two relays. Both relays are a 1" cubed black box with writing...

SHORI
S11-1A-C1-12VDC
30A/12VDC
COIL:12VDC

Is there a way to test the relay maybe? I have a multimeter but not enough knowledge to just jump into this.

Thanks