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Odd 7 pin wiring harness

Derick
Explorer
Explorer
Hi all - this isn't actually RV related, but it is trailer related. I purchased a flatbed from a co-worker over the weekend and I had to re-wire the 7 blade connector since it had been driven over (or something). I was able to get things working, but I wanted to run this by anyone who would know.

I have the following wires;

Yellow - Left Turn
Red - Trailer Brake
Black - Ground???
Blue - ???
Green - Right Turn
Brown - Tail/running lights

There are two things that are strange right out of the gate. First, no white/ground wire. I have black wired into ground right now, and while I dont think it would be anything else, I haven't yet verified that (ie, remove it, and see if everything fails). The other is that the trailer brake is on red...when everything says it should be on blue. The brakes indeed work, and it's recognized by the controller...but very strange. Right now, I have the blue wire not connected to anything, but I believe its the aux/charging circuit for the breakaway battery. Still need to verify that too.

That said, is there any sort of "other standard" out there that would explain, or at least validate what I've found so far?
18 REPLIES 18

Lynnmor
Explorer
Explorer
dougrainer wrote:
NONE of the previous schematics and even the Internet Links are WRONG for RV's. Just goes to show the Internet is not always right.

Brown----- RT
RED--------LT
BLUE-------Electric Brakes
WHITE------Ground
BLACK------12 volt positive
GREEN------Running Lights
YELLOW-----Center pin unused but if used Reverse lights.



The link to eTrailer, that I posted, showed exactly that!

Farmboy666
Explorer
Explorer
dougrainer wrote:
Farmboy666 wrote:
dougrainer wrote:
NONE of the previous schematics and even the Internet Links are WRONG for RV's. Just goes to show the Internet is not always right.

Brown----- RT
RED--------LT
BLUE-------Electric Brakes
WHITE------Ground
BLACK------12 volt positive
GREEN------Running Lights
YELLOW-----Center pin unused but if used Reverse lights.

Before you attempt to correct me-----I have wired and repaired miswiring on hundreds of 7 way RV trailers. Since this is an RV forum, the correct answer is posted above

Now, what confuses some people is 4 way BOAT or Utility trailer wiring
4 way flat is
YELLOW---LT
BROWN ---Running lights
WHITE----Ground
GREEN----RT

So, some know 4 way flat and then use the same colors when connecting to a 7 way plug. Which is wrong. Doug

Why donโ€™t you read the original post, he doesnโ€™t care whatโ€™s normal, he wants to know if anybody has seen a trailer wired like his.


If someone wired it wrong, then it is ridiculous to ask if someone has seen his wiring. I am telling him HOW to correctly wire HIS trailer so it will work on any vehicle that is correctly wired. Make it correct, not work around the problem. I was also responding to the mistaking wiring links so people will realize those links are wrong. Doug

Well heโ€™s the one asking if anyone has seen his wiring so your calling his question ridiculous? He has already stated he can google a wiring diagram himself without any help. Donโ€™t be so sensitive Doug, youโ€™ve been wrong before.

dougrainer
Nomad
Nomad
Farmboy666 wrote:
dougrainer wrote:
NONE of the previous schematics and even the Internet Links are WRONG for RV's. Just goes to show the Internet is not always right.

Brown----- RT
RED--------LT
BLUE-------Electric Brakes
WHITE------Ground
BLACK------12 volt positive
GREEN------Running Lights
YELLOW-----Center pin unused but if used Reverse lights.

Before you attempt to correct me-----I have wired and repaired miswiring on hundreds of 7 way RV trailers. Since this is an RV forum, the correct answer is posted above

Now, what confuses some people is 4 way BOAT or Utility trailer wiring
4 way flat is
YELLOW---LT
BROWN ---Running lights
WHITE----Ground
GREEN----RT

So, some know 4 way flat and then use the same colors when connecting to a 7 way plug. Which is wrong. Doug

Why donโ€™t you read the original post, he doesnโ€™t care whatโ€™s normal, he wants to know if anybody has seen a trailer wired like his.


If someone wired it wrong, then it is ridiculous to ask if someone has seen his wiring. I am telling him HOW to correctly wire HIS trailer so it will work on any vehicle that is correctly wired. Make it correct, not work around the problem. I was also responding to the mistaking wiring links so people will realize those links are wrong. Doug

bucky
Explorer II
Explorer II
A lot of equipment trailers don't use 7 wire connectors. Go to Tractor Supply and buy 2 things. A female 6 wire end and a converter to plug it into your 7 wire truck.
Open the package and read the wiring schematic to be sure, but I think that is the issue.
Puma 30RKSS

Farmboy666
Explorer
Explorer
dougrainer wrote:
NONE of the previous schematics and even the Internet Links are WRONG for RV's. Just goes to show the Internet is not always right.

Brown----- RT
RED--------LT
BLUE-------Electric Brakes
WHITE------Ground
BLACK------12 volt positive
GREEN------Running Lights
YELLOW-----Center pin unused but if used Reverse lights.

Before you attempt to correct me-----I have wired and repaired miswiring on hundreds of 7 way RV trailers. Since this is an RV forum, the correct answer is posted above

Now, what confuses some people is 4 way BOAT or Utility trailer wiring
4 way flat is
YELLOW---LT
BROWN ---Running lights
WHITE----Ground
GREEN----RT

So, some know 4 way flat and then use the same colors when connecting to a 7 way plug. Which is wrong. Doug

Why donโ€™t you read the original post, he doesnโ€™t care whatโ€™s normal, he wants to know if anybody has seen a trailer wired like his.

MEXICOWANDERER
Explorer
Explorer
He wants to know which color does what on HIS vehicle to Socket wiring harness(?)

dougrainer
Nomad
Nomad
NONE of the previous schematics and even the Internet Links are WRONG for RV's. Just goes to show the Internet is not always right.

Brown----- RT
RED--------LT
BLUE-------Electric Brakes
WHITE------Ground
BLACK------12 volt positive
GREEN------Running Lights
YELLOW-----Center pin unused but if used Reverse lights.

Before you attempt to correct me-----I have wired and repaired miswiring on hundreds of 7 way RV trailers. Since this is an RV forum, the correct answer is posted above

Now, what confuses some people is 4 way BOAT or Utility trailer wiring
4 way flat is
YELLOW---LT
BROWN ---Running lights
WHITE----Ground
GREEN----RT

So, some know 4 way flat and then use the same colors when connecting to a 7 way plug. Which is wrong. Doug

MEXICOWANDERER
Explorer
Explorer

2oldman
Explorer
Explorer
Derick wrote:
Yes, I can google, I know what they SHOULD be.....this is a thread on what they actually are.
Without being there and using a voltmeter, I wouldn't know.
"If I'm wearing long pants, I'm too far north" - 2oldman

MEXICOWANDERER
Explorer
Explorer
You have a classic and still very much in vogue T.T.M.A. Truck Trailer Manufacturers Association.

Wire harness color code arrangement.

Big rig. 18-wheeler

Blue is also used for power to the inside the van trailer ceiling lights AUX

Black is clearance lights

Brown is tail lights

Red is for stop lights

And 12 o'clock high is the big white pin for chassis negative

Derick
Explorer
Explorer
Yes, I can google, I know what they SHOULD be.....this is a thread on what they actually are.

Lynnmor
Explorer
Explorer

BFL13
Explorer II
Explorer II
Once the wires are sorted out for which pin is which, it remains there needs to be a way to keep the trailer's breakaway battery (mentioned in the OP it has one) charged up while the trailer is parked. IMO also do a test of that system by pulling the pin and see if it works (but not when the 7-pin is connected since that can fry the controller in the truck ISTR)
1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.

Farmboy666
Explorer
Explorer
ScottG wrote:
Blue is supposed to be the backup light circuit.

Blue is brakes and trailers rarely have backup lights because they would serve little purpose. I'm sure OP could find a wiring diagram as easily as any of us, the question was is the setup he has of any standard.