Hi everyone, just bought a new to me '19 F150 yesterday. We got it specifically to tow our travel trailer. Got home from the dealership around 9:30 last night and of course took it straight to hook up the camper. After connecting everything, I realized that none of the camper lights were on and the display in the truck said "trailer not connected". Made sure to go through the "add trailer" function (this thing is too smart for me LOL). I could never get the trailer to connect. I messed around for almost 2hrs, checking fuses, wiggling the 7 pin connect, cleaning the connector. I finally gave up and was going to unhook and go to bed. As I put the jack back down and starting taking some of the weight off the hitch, the light magically came on and the trailer connect per the instrument panel. Starting taking the jack back up, lost connection. I climbed under the truck and made sure all the wires looked OK and made sure the ground wire was secured to frame. All that seemed fine. Kept playing around with the jack, but could never get the connection to last with full weight on the hitch. I did notice that when ever I would disconned the 7pin and re-insert it, the instrument display would go straight to the trailer status screen, so it's sensing that the trailer is being connected, but when I tried to manually apply to trailer brakes, it says "trailer not connect" again. I'm 99.5% this is a grounding issue, but just don't understand why the full weight of the camper on the hitch interrupts that. I even jump a wire from truck frame to camper frame and the lights would come on. Anybody have any suggestions? I know that I'm probably beating a dead horse here, I've read through several of the other posts concerning grounding issues, but didn't really see anything that described this weird situation.

 

The ground wire is bad, when it works it is only connect through the hitch.

Disconnect the trailer and plug in the connector so the only ground is through there. Then start tracing, could be on the truck or the trailer. Do you have a voltmeter?

 

I'm not saying this is wrong, but I would think that if it was right, the ground would be more stable with full weight on the hitch. I do have a multimeter and plan to start tracing that ground when I get my next day off. My wife is currently on the truck and is going to run by my work to connect to an enclosed trailer here to try to narrow the problem down to truck or camper.

 

The analysis was spot on. Pressure on an electrical connection does not necessarily make a better connection. Grease, rust, dirt, ect. can all block electrical connections. Poor ground wire connections on the trailer frame side has been a problem on several trailers I’ve owned.

 

Ok, come to think of it, the male end of the hitch that slides into the receiver on truck is pretty rusty. So, I guess when the weight is applied he could be moving that hitch just enough to break continuity. Thanks for the help guys!

 

Yes, but the hitch shouldn't be providing ground for the trailer. You need to disconnect the 7-pin and check for ground continuity on the truck and on the trailer. If it's the truck, we can list the common areas to check. If it's the trailer, you will have to wire trace.

 

with ford system is almost always a bad ground that trips up the tbc and dash info
unhook trailer as mentioned and plug it in but dont let ball touch the truck. then chase wires.
i would look at the trailer break away battery and all the grounds. especially the one near the pig tail connection
i could write a novel on loss of ground over the years on all my fords since they started putting in the the tbc

 

I was able to sneak away from work and find the problem. The 7 pin cable on the camper went to a junction box. Took the cover off, found 4 white ground wires with a wire nut. As soon as I touched the wire nut it fell off. Put the wires back to gether and everything worked! Thanks for all the help!

 

Lordy... when will people ever learn.

Wire nuts are for non-vibration locations, as in, inside your home's walls. Don't use them in your trailers, and toss them when you find them.

Trailers with brakes get a terminal block screwed to the inside wall of the battery box. Ring connectors, blue lock-tite on the block screws. Provides a super convenient probe point, and easy access to replace problem wires. I've yet to have to replace any wires, though, as I always replace oem wiring at first issue with proper duty wire and run wet conduit where wire is exposed to the elements. Overkill, but cheap, easy, one-and-done.

 

Probably also worth mentioning if using crimp connectors make sure to use proper crimping tool. For example crimping an uninsulated connector uses a different tool than when crimping an insulated connector. Get the better quality connecters with heat shrink jackets. I have seen many crimp connectors fail from poor technic. BTW do not tin the wire for crimping…it will break at the point where the tinning ends over time.