babock

Hence the reason I said "Many".

BlueSpark

I typed a long, sarcastic reply because I’ve never had to re-wire a truck for any number of trailers I’ve pulled. Then I just decided to google.

The wiring pattern is standard. Center wire is reverse. See this link:

https://www.etrailer.com/question-32475.html

No one has yet answered how many wires must be connected for the 2018 BLIS Trailer mode to be triggered. Most posters have said that they have no problems when they connect aux back-up light wires to the center reverse wire. A very few (by doing a forum search) have had a problem. So, we do not yet know what actually tells the truck that there’s a trailer plugged in.

B-ManFX4

Actually, we do know - it is current flowing through the lighting circuits. There is no reason or need to detect current flow in the reverse wire - many trailers don't have reverse lighting anyway. ALL DOT-certified trailers have running lights and brake lights.

rliles1

Or this link from the same etrailer website where they explicitly state "The center pin on the 7 way connector can be used for many different purposes, although it is typically used to carry the signal from the reverse lights on the vehicle to the trailer." That makes it not a standard. You won't find any website stating that you can use the right turn signal/brake light wire "for many different purposes." THAT is a standard. The link you posted did name 5 vehicle makers that USE it for that. Again, that does not make it a standard. If you have to stipulate who uses it, that implies it can not always be trusted.

https://www.etrailer.com/question-7194.html

BlueSpark

And we’re here for F150s....

babock

Although I like etrailer and buy a lot of stuff from them, if I had a nickel for every mistake they post....I would have a LOT of nickels!

Ford GM and Ram all use the center connector for reverse. I guess if you search hard enough, you could find a truck that was wired different but I haven't seen one.

I have only had one trailer where I ever needed the reverse circuit and that was for a surge brake interlock that prevented disc brakes from operating in reverse. Very few trailers have reverse lights.

rliles1

I agree that this is all a semantics quibble. However, I strive for precision. I would not have even posted to this thread if it had been stipulated the "Ford reverse pin." However, when it was asserted that the center pin "WAS" a reverse pin without the implied or stated possibility that it may not always be the case, I pointed out that it was not an accepted standard. It is an accepted "FORD" standard, yes, but that was not my point.

I will sign out of this thread now. I have made my point for those who are learning, and won't make any headway on those who won't. If someone wants to post here that the center pin ALWAYS IS a reverse pin, you will have the last word. (And if you specify "on a Ford it ALWAYS IS," you will even be correct.)

(This is for BlueSpark - this response by you is the best response so far to my assertion.)

I agree. I only used etrailer because BlueSpark used etrailer. I wanted to use his same source.

(I do love a good debate.)