If you take the switch cover off, you can take the switch assembly off. I’d bet that all three share a common ground (white) and the power ( white with stripe) are jumpered between switches. I would start at the 12V coming in and the common ground.
2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.