Two lights one switch

Can I wire my lightbar and ditch lights to run off the same switch. I want both to turn both off and on at the same time. I don’t want to give up an extra switch blank to run something I could run off one switch. Both of my harnesses are relayed. My ditch light harness is 100% installed. Where and what would I splice into. I’m assuming I can splice the trigger wires together. Any help before I catch my truck on Fire?

 

If the relay, fuse and wiring for the ditch lights will support the additional current draw then just split the output from the relay to both sets of lights. If it won’t you can either upgrade all of it so it will or split the trigger wire from current switch to two separate relays.

 

What he said. I'd favor each having it's own fuse and relay but both relays can be activated by the same switch.