JMKerns

I am the proud owner of a 2013 Kodiak brown F-150 XLT supercab. I have recently started towing our 23" Carolina skiff to and from our local lakes. I recently converted my 5 blade plug to the 7 round plug to eliminate the use of an adapter. I wired everything up correctly but my trailer still wont back up on flat ground without loading up the trailer brakes. My trailer tongue actuator comes with the solenoid to delete the brakes when the truck is put in reverse. After testing the truck side of the plug with my volt meter I determined that the center pin/reverse light does not have 12 volts to it. Also the 12 volt constant on the truck side does not have voltage either. After studying my manual and under hood fuse panel I seem to have every relay and fuse I need installed except 1. The only relay that has anything to do with trailer wiring that is not present is #21 (trailer tow battery charge relay). To my understanding that shouldn't affect trailer reverse lights. I will try to grab one of those relays after work. If anyone has experienced this any info is appreciated. l browsed the forum and found a few threads discussing this topic but never an end fix. I also drilled a 1/4" in my brake slider to "pin" the surge brakes forward so i can still backup in an emergency. But this is 2018 in a late model truck and a newer boat....the technology exists. I just need a little guidance my friends. Below is a list of the fuses/relays that are installed and correspond to trailer wiring.

#6 trailer tow park lamp relay
#9 trailer tow battery charge relay I purchased saturday from Oriely Auto parts
#37 left trailer stop/turn relay
#38 right trailer stop/turn relay
#39 trailer tow back up lamps (THIS SHOULD ALLOW THE SOLENOID TO DISENGAGE THE BRAKES)
#43 Trailer tow back up lamp relay power (SEE ABOVE)
#67 trailer tow park lamps relay
#73 trailer tow stop turn lamps relay

P.S. I have tried 3 different local dealerships and no one will return my call.

BlackBoost

I can't offer help other than to ask if you tried connecting a filament light bulb to the reverse voltage pin to see if it lights up. I'm just wondering if the truck detect no load (just a voltmeter) so it doesn't send power.

Also, have you set your trailer in the dash to surge brakes? Not sure if that would make a difference but worth a shot.

The +12v not having power has been mentioned before by someone who wanted to use it to power some lights in a horse trailer. Again, I wonder if it's the trailer plug being "smart" and not powering it. Normally that pin is used to charge/maintain the battery in a travel trailer while towing. On my power meter in my TT, I can definitely see the voltage go up when I plug my TT into the truck with the 7pin. But I wonder if the plug senses no voltage coming back from a battery and will also kill the power...

Like2Hike

Try the website etrailer.com, they have a wealth of technical info.

seaeagle2

Do you have a "bypass" solenoid or a locking solenoid. On my boat, if I had my foot on the brakes when I shifted into reverse it would "lock" the brakes on. The bypass ones have an bleed line so the brakes don't work in reverse, the other style just locks the brakes in whatever state they're in when you shift into reverse.

W3BY

I have to ask. Is there 7 wires going into the connector on the truck side? They sometimes do not run wires for 'backup lights' and 'constant power' to the 7 plug connectors. Look under the truck for the wiring harness, near the spare tire, and see if all the wires are run to the trailer connector. I hope this helps and is a great place to start.

Steve83

(phone app link)