fremont

I'm trying to hook up a VHF/UHF radio using this diagram. Does an '18 Silverado have a battery power monitoring feature (same as "ELD" in diagram)? I know I've got a voltage meter but unclear how it hooks up or whether it's synonymous with what the diagram calls ELD.

I can see two negative wires coming off battery terminal towards frame. I'm assuming large negative goes to bolt on frame; where does smaller negative go?