Trailer Electrical Connector - Wiring Harness

[SC Tiger]

My dog ate the wiring harness on to the 7-pin connector on my 2000 Silverado.  While fixing it, I reconnected all of the wires but I found one in the harness that didn't seem to have a home on the plug.  It's a light blue wire, approx 16-18 AWG I believe.  All of the other wires were broken at least an inch from the plug, so I knew where they went.  But this one wire doesn't seem to have a home.  I assume it shared a pin with one of the other wires, but I cannot figure out where.

 

Anyone have any ideas what this might be?

 

 

[dna9656]

I would check a GM wire diagram, you can prolly find on on line....maybe call your local GM or trailer dealer?

[slj2008]

6 hours ago, SC Tiger said:

My dog ate the wiring harness on to the 7-pin connector on my 2000 Silverado.  While fixing it, I reconnected all of the wires but I found one in the harness that didn't seem to have a home on the plug.  It's a light blue wire, approx 16-18 AWG I believe.  All of the other wires were broken at least an inch from the plug, so I knew where they went.  But this one wire doesn't seem to have a home.  I assume it shared a pin with one of the other wires, but I cannot figure out where.

 

Anyone have any ideas what this might be?

 

 

brake controller - blue wire . 

[SC Tiger]

13 hours ago, slj2008 said:

brake controller - blue wire . 

There are two blue wires.  A heavier-gage blue that I have connected, but this is a second one.  I would assume it would tie into the other blue, but I don't want to actually do that until I know for sure.

 

So basically I have 8 wires going into a 7-pin connector.

 

I did test the connector with a 4-pin adapter and everything seems to work right.  So it is in the trailer braking system or something not used on those.

 

I should also add that this is the GM towing package setup from the factory.

17 hours ago, dna9656 said:

I would check a GM wire diagram, you can prolly find on on line....maybe call your local GM or trailer dealer?

I haven't been able to find one online yet.  I guess I could call the dealer but I'm trying to avoid that, honestly.  

 

I'm wondering if there was something else under there that the dog ate, or if it went to something else under there that I'm missing.  

[dna9656]

https://duckduckgo.com/?q=round+7+trailer+wire+diagram&t=newext&ia=web

[richard wysong]

it doesn't look like any of those show 8 wires going to the 7 pin plug so you may need the factory diagram

[SC Tiger]

13 hours ago, richard wysong said:

it doesn't look like any of those show 8 wires going to the 7 pin plug so you may need the factory diagram

I'm going to poke around and see if that wire went somewhere else and somehow got bundled up with these.  I kinda doubt GM would just throw an extra wire in there that doesn't go anywhere, but who knows.

 

The plugs for the wiring harnesses that go to the back of the truck (tail lights, etc) are right above this area so maybe it came from there?

[asilverblazer]

IIRC its for a backup light. Not typically used on the seven pin connector.

[redvett]

Try the GM wiring. 

https://www.google.com/search?q=gm+trailer+wire+colors&hl=en&sxsrf=ALiCzsbOtmePqUAjWsfYOd4pgOxPiFQfcg%3A1659476368589&source=hp&ei=kJnpYqbaHYHXkPIPzoaMmA0&iflsig=AJiK0e8AAAAAYumnoMEF9v-u1aaVHhA0M8hUYSPRNDTO&oq=gm+trailor+wire+&gs_lcp=Cgdnd3Mtd2l6EAEYADIECAAQDTIGCAAQHhAWMgYIABAeEBYyBggAEB4QFjIGCAAQHhAWMgYIABAeEBYyBggAEB4QFjIGCAAQHhAWMggIABAeEBYQCjIGCAAQHhAWOgcIIxDqAhAnOgQIIxAnOgsIABCABBCxAxCDAToRCC4QgAQQsQMQgwEQxwEQ0QM6CAgAELEDEIMBOggIABCABBCxAzoFCAAQgAQ6CwguEIAEELEDEIMBOggIABCABBDJAzoFCC4QgAQ6BAguEA06CAgAEB4QDRAFOggIABAeEAgQDToKCAAQHhAPEBYQCjoICAAQHhAPEBZQ6glYs6EBYIzAAWgCcAB4AIABmAGIAecOkgEEMi4xNZgBAKABAbABCg&sclient=gws-wiz

[SC Tiger]

 

On 8/3/2022 at 12:46 PM, redvett said:

Try the GM wiring. 

https://www.google.com/search?q=gm+trailer+wire+colors&hl=en&sxsrf=ALiCzsbOtmePqUAjWsfYOd4pgOxPiFQfcg%3A1659476368589&source=hp&ei=kJnpYqbaHYHXkPIPzoaMmA0&iflsig=AJiK0e8AAAAAYumnoMEF9v-u1aaVHhA0M8hUYSPRNDTO&oq=gm+trailor+wire+&gs_lcp=Cgdnd3Mtd2l6EAEYADIECAAQDTIGCAAQHhAWMgYIABAeEBYyBggAEB4QFjIGCAAQHhAWMgYIABAeEBYyBggAEB4QFjIGCAAQHhAWMggIABAeEBYQCjIGCAAQHhAWOgcIIxDqAhAnOgQIIxAnOgsIABCABBCxAxCDAToRCC4QgAQQsQMQgwEQxwEQ0QM6CAgAELEDEIMBOggIABCABBCxAzoFCAAQgAQ6CwguEIAEELEDEIMBOggIABCABBDJAzoFCC4QgAQ6BAguEA06CAgAEB4QDRAFOggIABAeEAgQDToKCAAQHhAPEBYQCjoICAAQHhAPEBZQ6glYs6EBYIzAAWgCcAB4AIABmAGIAecOkgEEMi4xNZgBAKABAbABCg&sclient=gws-wiz

Found it on the search results.  It's a dedicated wire for the high brake light on a camper shell.  So I don't need it.  But I still wonder where it was connected - or was it just sorta there loose in the bundle?

 

Either way, I'm not going to any trouble to fix it.  Thanks.

[asilverblazer]

"Blunt cut", taped in the bundle.