OK...Now I feel like I have lost my mind.

I bought my truck with no reciever, and just the 4 pin flat trailer harness on it. Awhile back, I went to a salvage yard, and picked up a receiver from a same year F150, along with the 7pin round harness, (factory harness). Well I switched out the harness from the 4 pin to the 7 pin, and I finally went to use the 7 pin on a trailer my uncle left me. No lights on the trailer at all. I checked all the outbound voltages from the truck and they all checked out. Checked voltage AFTER the trailer harness for one light and it was good but at the light itself on the trailer, showed grounded. So I am going to re-wire the trailer. Anyway....checking further into the harness on the truck, I did notice the 12volt was not active, nor was the backup point, (center pin). Now I know the trailer brake point isn't going to be active since I have not hooked up the brake controller yet. But I want to make sure I am not missing anything. So here are my questions along with pics of the Battery junction box and the central junction box. (Check gallery for pics)

1 - Am i missing anything for the 12v to charge trailer battery?
2 - Missing something for the backup lights?
3 - Missing something for the trailer brakes?
4 - Would the outbound from the brake controller to trailer have to be wired to the connector on the bumper or is there a connecting point under the dash?

I don't want to start running a load of wiring from battery to back etc. I want to use as much of the factory setup as possible.

I have scanned the posts but I didn't find anything with too much detail about all this. What should I be looking for?

 

all the wires are in the truck harness from the dash to the plug on the divers side of the spare tire (on the frame). if you get the 4 pin factory rear connector, you get the basic small rear harness. if you get the 7 plug setup, you get the complete harness that plugs into the big plug by the spare tire, and you also get a couple relays that go in the box under the dash and turn on the 12 volt power to the rear plug. the trailer brake wire is already there. i did this to mine, there is a 4 pin plug under the dash by your right knee that plugs into your brake controller. i dont have the wire colors right now, but most brake controllers can be bought with a "ford" plug to go into the truck plug under the dash.

 

https://www.ford-trucks.com/user_gal...104443&width=2

For starters:

Strictly comparing your gallery photo above to a battery junction box diagram (for a 1999 F150), it appears you are missing the trailer tow battery charge relay, and the trailer tow reversing lamp relay.

 

R8rvectors.....Thanks! I finally found my way through the Ford service DVD for my truck and found the info. I see the two I am missing.

Steve... Thanks for the info. I have a service DVD for my truck, so now that I know what to look for, I can get the wiring color codes. My truck started with the 4pin flat connector, but I switched it to a factory 7 pin that just replaced that small section of the harness at the back of the truck.

 

OK...Quick update....my DVD doesn't show the connector itself. Just lists one wire listing to the controller, (aftermarket). Anyone know what the rest go to? there are a total of 5 wires on the connector by my right knee. Would be great if I could run all the wires from the controller to that one spot.

 

Nevermind the connector pinouts. I found through a parts listing that Ford has a "Brake controller Adapter" the is a pigtail that plugs right into that harness. Just mtach the colors of the pigtail to the colors of the wires on the brake contorller...mount and away you go. Going to the dealer today. I did find it for $10 on the web, (trailer parts site), but I kind of need it today so I am willing to pay the extra from the dealer.

 

for anyone that does not have the FORD DVD for a F150 truck, i recommend it highly. I bought one on e-bay for $7. dont have everything, but sure gets you started in the right direction. i used it for ball joints, trailer wiring, transmission- torque converter oil drain (mine had the converter plug).---- very helpful.

 

AMEN!!!! it has helped me more than once.