Scottdunl 2007-08-25 20:37:23
I’m not sure what the out puts are on the F150 lights for a 4 pin. I
can’t get the running lights to work. I can get the turn signals and
brakes to work with the headlights on. Again, no running lights.
Samstone 2007-08-25 20:37:31
you have three of the four already – so a volt meter or a 12v test lamp
would indicate them for you
you have a ground – the left turn/stop – the right turn/stop and the running lights
Samstone 2007-08-25 20:37:33
Scottdunl 2007-08-25 20:37:36
Thanks for the quick response. I have never used a forum like this and
it paid off. Thanks again!!!
Scottdunl 2007-08-25 20:37:39
Ok I lied, that didnt work at all. Any other help?
Spdloader 2007-08-25 20:37:42
Get a test light from an auto parts store.
Turn on just the running/park lights on your truck.
Ground your test light, then probe the wire harness at either rear light,
done easiest with the taillight assembly out.
When your test light lights up, you’ve found your running lights for your
Connect it to the Brown wire on your trailer kit.
If you need further you can email me direct using my knick below, then
Samstone 2007-08-25 20:37:44
What do you mean by “that”?
Are both elements in both trailer bulbs OK?
Lugnut 2007-08-25 20:37:47
The best way to do the job is with an adapter that simply
plugs into the harbess below the tailgate and is already
wired correctly. Takes about 2 minutes for complete job.
Almost any store that sells anything related to trailers,
boats or auto parts should have the adapter. Then you won’t
have a sliced and diced harness to cause further problems
later down the road.
Jeff stricklan 2007-08-25 20:37:50
The wire harness for a 4-pin connector is included with the connector.
WHT – Ground
BRN – Lights
GRN — Right turn and stop
RED – Left turn and stop
Jeff stricklan 2007-08-25 20:37:53
You have a wiring problem in the trailer associated with improper grounding.
You described exactly the problem of a poor ground. The trailer’s stop and
turn lights are getting a ground WHEN THE LIGHTS ARE ON through the running
light circuit in the truck. If the lights are turned off, then the brake and
turn indicators stop working too. (Actually, as I write that, it occurs to
me that symptoms should be exactly opposite — the brake and turn indicators
work when the lights are off, then stop working when the lights are on.)
You have a grounding problem in the trailer or you have the wrong light
bulbs in the trailer. Odds favor a bad ground over the wrong bulbs. Your
bulbs should have two filiments in each, and the number stamped on the base
should be 1157.
On the trailer wiring harness (connector), WHT is ground. BRN is running
lights, GRN is right side turn and stop, YEL is left side turn and stop. A
common problem is that some guys bring the white wire into the trailer, but
do not select a suitable grounding method. You must put a good terminal on
the end of the wire, then use good star washers to poke through the paint
and press into the metal. (Paint is an insulator.) You should really scrape
the paint away from the grounding terminal to make a quality connection
point. Once you have your system working, then you can come back and paint
over the connection to preclude rust. It’s a good idea to cover the
grounding point with tape before painting, then remove the tape to establish
the ground point. This is actually better than painting over a ground
Then, you have to ensure that the tail light housings are grounded well to
the trailer itself. This is a huge problem with trailer lights, they ground
through the mounting screws to the trailer itself, but the mounting points
are not qualified to provide the needed ground circuit. You might be
required to hardwire a ground from the housing (lamp base) to the trailer
frame. You _could_ bring the white wire from the connector all of the way to
the lights, but usually the white wire terminates on the tongue and the lamp
housings are then grounded to the frame of the trailer. If you wire this
way, then you will have GRN and BRN to the right side, and YEL and BRN to
the left side
CORRECTION TO AN EARLIER POST
I might have said that there is a RED wire to serve the stop and turn
indicator on the left side, this is an error, the actual wire color for that
circuit is YEL.
Trailer wiring is standardized, and a 4-pin wiring harness (by far the most
common) has WHT, BRN, GRN, & YEL. The arrangement of the wires in the tow
vehicle is important because because one might tow a different trailer some
day, and one would want any trailer to easily connect without having to
rewire something everytime the trailer changes.
Most trucks already have a 4-wire plug on them, whether or not they have a
trailer tow package on them. I don’t recall that you mentioned which year
your F150 is, but I have a ’95 Bronco that has a trailer connector, and my
previous ’95 Bronco also had one — they are both 6- or 7-pin designs, and
could be the result of a tow package. I’ve been shopping for F150s in the
past two or three years, and I noticed all of them on the lot that I was
looking at had trailer connectors on the truck.
When you buy a flat 4-pin connector from WalMart, or anyplace else, the
arrangement of the wires will always be the same, and any trailer will also
be the arranged the same way. The idea is that you should be able to hook up
any trailer and drive away, and the lights should work. Surely one would not
want to hook up to a trailer and have it start blowing fuses in the tow
vehicle, and this requires you to wire your connector the same way everybody
else wires them.
Jeff stricklan 2007-08-25 20:37:57
The RED wire is really YEL.
The trailer wires are WHT, BRN, GRN, & YEL.
Steve barker 2007-08-25 20:38:05
And just for informational purposes, I have always remembered the right and
left this way.
Green has 5 letters, RIGHT has 5 letters
PORT has 4 letters, LEFT has 4 letters.
Samstone 2007-08-25 20:38:24
Brown and White also have five letters.
What has port got to do with anything?
We’re not lighting a boat.
Steve barker 2007-08-25 21:23:02
brown and white were never the confusing part.
I just thought I’d throw that in about the port thing.
Jeff stricklan 2007-08-25 21:23:14
One can abbreviate wire colors with 3 letters and not have any danger of
confusing one color with another.
Brown and white also have 5 letters.
Yellow has 6 letters, and defines the brake and turn indicator wire for the
left side of a trailer.
I am having trouble understanding what your point is.
Steve barker 2007-08-25 21:23:17
You’re having trouble understanding. Let’s just leave it at that. I can’t
make it much simpler.
Jeff stricklan 2007-08-25 21:23:42
You offered no new information that is 1.) corrrect, or 2.) applicable.
Thanks for playing though.
Whitelightning 2007-08-25 21:23:47
PORT wine is red 😉
Steve barker 2007-08-25 21:47:50
Look you dumass b******. I merely made a comment as to an easy way to
remember which is which between the green and yellow on trailer light
So F*** off.
Jeff stricklan 2007-08-25 22:23:03
Except, your easy way to remember is WRONG. GRN is right, YEL is left.
I see no need for profanity.
And, it’s dumbass b******, dumbass.
Steve barker 2007-08-25 22:23:06
that’s what I said about 18 messages ago. green has 5 letters, right has 5
letters. a good way to remember. I never once said it wrong.
Samstone 2007-08-25 22:23:08
shows green as the running lights tho there is one of those on the right, right?
and i know nothing of wine be it port or starboard
Jeff stricklan 2007-08-25 22:23:32
But YELLOW goes to the left side, and you gave another color in your
I agree you gave the right color to remember the right side, but you gave
the wrong color to remember the left side. I gave you the actual color for
the left side, and you got nasty.
Samstone 2007-08-25 22:23:35
Here’s a bit of info.
at the bottom of that site there is a read out from factory wirings
on different manufactures. ( what color wires ford uses on the
left/ right/ running lights)
Also there seems to be no convention set for the trailers wiring
other than white being the ground. Yellow seems every time to be left,
but the green and brown switched from running to right on different sites.
The flat four pin connector on this etrailer site doesn’t even try to suggest
what is what .
So I guess the best way would be to inspect the trailer bulbs wiring and see
how that manufacturer wired it.
Steve barker 2007-08-25 22:56:06
No I didn’t. I threw in that PORT was left. If you ever noticed, PORT is
not a color. It is a marine term for the left side of the boat. It was
supposed to be humorous. Apparently you didn’t get it. I just threw that
in because it is a good way to remember PORT from STARBOARD. Port has 4
letters, Left has four letters. Has nothing to do with trailer lights,
granted, but was put out there anyway.
Steve barker 2007-08-25 22:56:09
Anyone using green for running/tail or brown for a turnsignal/brake is just
flat doing it wrong. Sure some trailer manufacturers do it that way, but
that doesn’t change the standard.
Jeff stricklan 2007-08-25 23:27:10
Apparently not. Maybe it was humor challenged.