- 1). Insert the four- to five-pin adaptor into the preexisting flat four-pin hitch connector by pressing the matched terminal ends together until you feel a positive resistance.
- 2). Locate the tow vehicle's backup light wire. Backup light wires are typically solid purple or purple with a pinstripe; consult your owner's manual to confirm the color code. The wire is usually most easily accessed behind one or both rear lamp clusters.
- 3). Connect the loose wire from the four- to five-pin adaptor to the tow vehicle's backup light wire. Use a cable splice and insulate the join with electrical tape, or strip a half inch of insulation from the end of the new wire and at a random point along the preexisting wire then twist them together, solder the connection and insulate the join with a shrink-wrap kit.
- 4). Route the five-pin end of the adaptor to a location close to the tow hitch, and secure the run of wire away from hot and moving parts using cable ties.
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