4 pin trailer wiring
Cargo Master
Joined: Aug 2004
Posts: 2,542
Likes: 22
From: Murphysboro, IL
The bare one is your ground, one of them will be your tail lights/running lights, another will be your right turn signal/brake light and then the other will be your left turn/brake light.
I don't remember off hand which is which but I think the one closest to the ground is your tail lamps, the next is your left turn and the far right (with your groudn to the left) is your right turn. I could be and probably am wrong on that one but it gives you a general idea.
If something is stuck in it try to pull it out with a pair of needlenose pliers, if it's dirt or mud then use WD-40 and a pipe cleaning rod/pick/screwdriver etc. I've used almost anything to clean them out.
I don't remember off hand which is which but I think the one closest to the ground is your tail lamps, the next is your left turn and the far right (with your groudn to the left) is your right turn. I could be and probably am wrong on that one but it gives you a general idea.
If something is stuck in it try to pull it out with a pair of needlenose pliers, if it's dirt or mud then use WD-40 and a pipe cleaning rod/pick/screwdriver etc. I've used almost anything to clean them out.
Senior User
Joined: Jan 2002
Posts: 201
Likes: 0
A trailer builder told me this one once.
The yellow wire is the left turn/brake which is near the yellow stripe in the road.
The green wire is the right turn/brake which is near the green grass on the side of the road.
The remaining insulated terminal is the brown wire which is the running lights.
The un-insulated terminal is the white wire which is the ground.
The blue wire in a 5, 6 or 7 pin connector is the brake wire. The rest I have to look up.
Hope this helps!
The yellow wire is the left turn/brake which is near the yellow stripe in the road.
The green wire is the right turn/brake which is near the green grass on the side of the road.
The remaining insulated terminal is the brown wire which is the running lights.
The un-insulated terminal is the white wire which is the ground.
The blue wire in a 5, 6 or 7 pin connector is the brake wire. The rest I have to look up.
Hope this helps!
