Tow Package Functions Not Working After Installing 7-Way on 2001 Ford F-150 that came with 4-Way

Question:

i have a 2001 ford f150 lariat super crew cab 5.4. it has a towing package with 4 pole boat plug. i bought a new travel camper so I upgraded to 7 pin plug 118242. everything is plug and play. watched the video did what they did. only problem im having is when I test my plug. only thing getting power is brake controller. checked all fuses and none is blown. no owner manual. what do I do now

asked by: David W

Expert Reply:

So when you say that the only thing working was power from the brake controller does that mean that the light functions are also not working? Or do you mean out of the new functions the reverse light and 12 volt circuits are not working? When you installed harness # 118242 did you install the relays? I assume you did but it never hurts to ask. If a relay is missing or bad that could be the problem.

In the in-cab fuse panel, location 23 there is a fuse for the 12 volt circuit relay. Under the hood in location 5 there is a fuse for trailer reverse and parking lights. Location 19 is for right turn and brake lights and location 20 is left turn and brake lights. Location 101 is for the 12 volt circuit. Location 201 is the parking lamp relay. Location 203 is the reverse light relay. Location 302 is the 12 volt circuit relay.

If any of those is bad or missing then that function will not work. It is also possible that while the connector from the new wiring harness plugs in the wires for the missing functions are not run all the way to the vehicle side plug that 118242 plugs into. I have included a link to a help article that, in part, explains this.

expert reply by: Michael H