tail light wiring
 

i was wondering if anyone had any wiring info for the rear tail lights on an 03 f250 xl

i have two black wires, one brown, one orange/gry and one pinkish/blk.
my haynes manual says that there should only be brown and grey for basically everything

any help?

I don't know what the black wires are, but the brown is tail/running lights and the orange/grey and pink/black are turn signals.

Where are you seeing these?

There should be a pigtail to the driver's Rear underneath of the bed frame, almost above the spare tire. I just had the whole harness out to rewire mine for the goose neck AND the bumper hitch. I don't think your looking at the correct harness, but mine is a '99. I would assume they stayed the same thru 04 at least. There will be a total of 7 wires, however some/all may be taped back into the loom depending on your current setup.

Attachment 202634

Those 7 wires are for the trailer connector. They are separate circuits from the tail lights themselves.

The black wires are the grounds. I missed those on the diagram the first time around.

silly me, He said Haynes and i was thinking trailer connectors, not repair manuals.

yeah, i bought a haynes to help out with stuff but so far it has proved useless.
so,
the brown wire comes on with the headlights only?
im trying to wire some aux lighting with the headlights

out of curiosity, how do the brake lights work?
i accidentally used the orange/gry one and it comes on with the brakes and with the right turn signal.
what if i only wanted brakes? would i have to connect to the green one from the CHMSL (third brake light)

The brown wire comes on with the running/marker lights. So that would technically be the switch position before the headlights if that matters. The brake lights use the same filament as the turn signals. If you want a brake light only, there is usually a blunt cut wire coming out of the wiring loom under the bed towards the rear somewhere that is labeled CHMSL.

great!
the other way to get brakes only (in this case) would be to have an OR gate and use both turn signals as inputs. however if you had a turn signal with no brakes, then you would still get flashing, but it would go solid as soon as the brakes were applied

edit:
just realized that i could also use the liscence plate lamps as headlight-on signals.
ok

Hi, I am trying to wire in a older welding bed and I am finding that the turn signal power runs back through to the brake lights on the oposite side. I have found the wires that run just the brake lights, but because ford has the turn signal combined with the brakes it closes the cuircut back through the brake light when just the blinker is on? Anyone know how else I can run older bed with just turn signal without brakes ?

rear wiring harness
 

hi, I was under my 04 f 350 xl with the 6.0 powerstrke in it and noticed that one of the wires that is apart of the rear lighting harness has six wires running to it and six coming out. of those six there is a green wire that seemed to have an end on it but there are no other corresponding solid green wires going out to the light. everything on the truck works as far as signals and brake lights. I was wondering if that's a chasis ground that needs to be reconnected? thanks

Just a guess but maybe it is for a high mount brake light if you add a canopy?

Use a test light, or buzzer to check it. You may need a helper.

Please help
 

Im trying to figure out which wires which on my tail lights wire harness to run some jump wires. My left brake and turn signal arent working. Just need to know whate the brown, black, light green with orange wires are for.

Brown is running lights on my 07, I remember that from when I added the dually light bar under my tailgate.