Hi folks & Tech Exchange editor. I just bought a 2003 Chevy S10 Ext Cab 4.3l v6 Fleetside with 89k on it. I bought it to haul a small travel trailer (1000 lbs dry weight). Looking around underneath the rear end to check hitch & wiring options and saw the following. Wondering what two items are - first the wire with the blue cap/cover (to the left), also the round, black box mounted to frame (to the right). (In the middle is the rod that is turned to raise/lower the spare.) Appreciate any help.