There should be groups of hot wires, wire nutted/crimped together behind the panel. Tap into one of those. On our unit some of the switches operated items that made no sense. For example; the front pin box light came on with the side scare lights. You can easily rewire by simply moving wires around. There are hot wires going to the switches and from them to each location. I took the wire that went to the pin box light and moved it to the step light switch. Now they come on together.
2018 Chevy 3500 LTZ Dually Diesel 4x4 CCLB
2011 Montana 3455 SA. 6 point level up. Disc brakes. Curt Q24 Hitch
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