Lights connection water greif

[ArlyA]

Silly question you guys. The trailer connection in our ford seems to gain moisture over winter months and the truck keeps telling us"trailer is connected" followed by "trailer is disconnected" over and over again. Of course we us liberal amounts of electricital grease on those connection's. Does anyone else have this greif?? What do you do for that? Our truck lives outside.

 

[LD1]

Is it a molded plug or a replacement type?

If replacement type, check the condition of the connections inside the trailers 7-way plug

 

[ArlyA]

The trailer is not connected. It's moisture in the bumper connection which is OEM.

 

[RandyT]

My dodge started doing that last year when the integrated brake controller failed.

 

[BleedingOrange]

With the truck off, use a small flat bladed screwdriver to spread each of the 7 male pins a little wider, which will help make a better connection. I do that on my Ford truck every late fall.

 

[ArlyA]

The truck brain's thinks there is a trailer attached when there's not. This only happens when there is moisture and some conductivity in the trailer connector on the rear of the truck. This only happens over the winter and today, I sprayed some WD 40 in it which is a dryer and that fixed it. That spray is a mess.

 

[Slowpoke Slim]

It could be coming from further up the wiring harness than the actual bumper connector plug.

If I remember right, there is another plug in the harness somewhere (depending on year) underneath the truck bed, usually near the gap from cab to bed.

 

[ArlyA]

The truck brain's thinks there is a trailer attached when there's not. This only happens when there is moisture and some conductivity in the trailer connector on the rear of the truck. This only happens over the winter and today, I sprayed some WD 40 in it which is a dryer and that fixed it. That spray is a mess.

 

[ArlyA]

It could be coming from further up the wiring harness than the actual bumper connector plug.

If I remember right, there is another plug in the harness somewhere (depending on year) underneath the truck bed, usually near the gap from cab to bed.

We're pretty sure it's in the bumper connector thingy. Ford people said the same thing.

 

[RustyA]

Not knowing the age of the truck my guess is you might need to replace the 7 pin/4 pin along with the lead in wire that attaches to rear wire harness. Depending on year and model it is generally one part complete with modular wiring. Be sure to use some dielectric grease on harness where it connects to existing wiring harness.

 

[dodge man]

I’ve got an F150 so I know what you are saying with the trailer menus. If it’s like mine you name the trailer if you want, for mine it’s “car trailer”. I know when I open the little door for the trailer hook up it can look pretty crappy in there but so far no problems. As you’ve discovered WD40 has a way of attracting dirt. They make a spray on electric cleaner, the last I bought at Radio Shack but they are long gone.

 

[ArlyA]

I’ve got an F150 so I know what you are saying with the trailer menus. If it’s like mine you name the trailer if you want, for mine it’s “car trailer”. I know when I open the little door for the trailer hook up it can look pretty crappy in there but so far no problems. As you’ve discovered WD40 has a way of attracting dirt. They make a spray on electric cleaner, the last I bought at Radio Shack but they are long gone.

CRC does make a cleaner/dryer cleaning spray product that is non-conductive which we could not locate at the farm/fleet store we stopped at yesterday. Maybe I'll need to ordered it on line..... Oh well.

 

[ArlyA]

Seems many responders have not understand the problem so I'll list in greater detail.

This 2019 ranger ford "thinks" there is a trailer attached when there is no trailer attached. So the main display on the dash says "trailer is connected" followed by "trailer is disconnected" over and over again. The ford dealership and myself thinks that moisture in the bumper trailer wiring connector makes the trucks brains think there is. I'm looking for a way to get this moisture out. When looking inside the trailer connector, looks fine to me. Just lots of non-conductive grease. This only happens over the winter and when I spayed the connector with the dreaded wd-40, it went away.

When a trailer really is attached, the truck always knows its there.

 

[dodge man]

I don’t know for a fact but my guess is the problem is elsewhere.

It’s been a few months since I’ve had a trailer connected so I don’t remember exactly how the menus read. Most of the time when I disconnect the trailer the truck knows it but sometimes I have to go into the menus and tell it no trailer. It’s a one time thing though, so that doesn’t seem like your issue.

 

[RustyA]

Now that we know it's a 2019 Ranger odds are less that it's a corrosion concerern. I would separate the harness connection, spray with electric cleaner CRC from Napa, apply dialectric grease, repeat for 7 pin/4pin sockets. I assume the Ford dealer checked for updated trailer module software that might address the problem?

 

[Oaktree]

So how does the truck know there's a trailer attached? I presume by sensing the electrical load of the tail lights? Must be pretty sensitive to allow for LED lights. If that's how it works, it wouldn't take much moisture/dirt to cause enough leakage to fool the circuit. A good shot of contact cleaner followed by dielectric grease might solve it.
IMHO, but just another technical "solution" to a non-existent problem that's just one more thing to break.

 

[dodge man]

I’m not sure how it knows. It doesn’t take any of the lights to go on before it knows something is plugged in.

 

[RandyT]

From my understanding it is sensed through electric pulse waves through the electric brakes. Basically it senses a complete circuit in the electric brakes when the trailer plug is connected.

 

[ArlyA]

From my understanding it is sensed through electric pulse waves through the electric brakes. Basically it senses a complete circuit in the electric brakes when the trailer plug is connected.

We have no brakes, so i surmised its senses the low draw of led lights. As soon as one starts the truck, the dash says "trailer is connected" if you plugged them in. Its actually a fine system which works perfectly well until a tad of conductive moisture gets into the trailer plug. (on the truck)

 

[MossRoad]

Are you sure you don't have a trailer connected?



Sorry. Couldn't resist.

If you don't have one, a trailer light tester is a handy tool for under $15. It may help you find which wire(s) are having issues, which could indicate where the water you suspect might be.

If it was bothering my that much, I'd start with a good spray of circuit cleaner several times. If that didn't work, then see if the thing is able to be disassembled easily. If it is, disassemble and clean out. If not, maybe look into replacement. No idea the price of that connector.

As others have said, maybe there's another connector upstream of it that could be the culprit as well.

Good luck. These kinds of problems can be perturbing.