I have a few questions of my 2016 F150 Lariat 3.5 Ecoboost
1. What fuse and relay do I need to purchase to enable the trailer tow charge through the 7-pin connector?
2. Which places in the fuse box do I put the fuse and relay to complete this?

Thank you.

Have you looked in your owner's manual? Have you checked the glove box for a bag with fuses and relays in it? I know they used to throw that in at the factory in trucks with tow package.

Yes. I looked on the glove box. It has the dust
cap for the back up camera in case I want to take off the tailgate.

As as far as the manual, there is nothing in the manual for the relay, fuse, or where they go in the fuse box.

My 2014 manual shows where the 30A fuse and relay go. They are inserted in the "power center", a fuse box in the front of the engine compartment.

If you bought your truck used, the previous owner may have taken them out of the glove box, that's where I found mine though. I'm sure your dealership would have the correct fuse and relay and would be happy to tell you where they go.

Here's another thought - maybe Ford has gone to a an abbreviated form of the owner's manual that does not show fuse locations. I found this to be the case with my Honda. There SHOULD be the complete owner's manual online, however, that can be downloaded in .pdf form. Do an internet search for the owner's manual for your 2016 F-150 with Ecoboost.

- Jack